The internal combustion engine, utilising oil-derived fuels, invented in the late nineteenth century, was the basis for the mass motorisation of society, which was a dominant feature of the twentieth century, and for the way most of us now live and inter-connect. Within less than a hundred years this originally complicated and unstable piece of kit was developed to high standard of performance and reliability – a considerable achievement by the world’s auto manufacturers and fuel suppliers. But now, what was thought to be an enduring technology, is in flux, with uncertain outcomes for both manufacturers and users of road vehicles. Major decisions are having to be made about a switch to electric propulsion and the automation of vehicle controls, with global industrial, societal and environmental consequences; and business (and public policy) disrupting penalties for those making the wrong choices.

In this blog I look at the implications of this critical time of change for both the propulsion and control systems underlying our deeply entrenched relationship with motor vehicles – and what the governmental role should be. 

Vehicle electrification

The switch of road vehicle propulsion from internal combustion to electric power is being driven by the need to decarbonise road transport, substantially and quickly cutting its contribution to climate change. In pursuit of this goal the UK’s  Zero Emission Vehicle Mandate, put in place by the previous government, requires 22% of new cars sold this year to be zero emission, rising each year to reach 100% in 2035. Under international agreements begun with the Paris COP accord on Nationally Determined Carbon contributions in 2015, similar requirements are in place for most developed economies, although the mechanisms vary. The car manufacturers are responding by developing new models, although UK firms are finding it hard to meet the current government-mandated requirement in terms of annual electric vehicle (EV) sales. Even though approaching year-end, 22% of new car sales are battery EVs, nevertheless the industry has pressed for a relaxation in the year-by-year targets. In response to this plea, the government recently said it intends to launch a consultation on the scope for flexibility, while remaining committed to phasing out sales of new petrol and diesel cars by 2030. 

The change to electric propulsion is causing a major shake-up to the global auto industry. Modern EV development emerged at the end of the 20th century in response to oil market crises and growing climate concerns. Starting with the Toyota Prius in 1997, the 2000s marked the development of hybrid vehicles (with batteries working alongside the internal combustion engine), the popularity of which has persisted to mitigate concerns about the driving range achievable with pure battery EVs. Tesla pioneered the development of commercially attractive battery EVs, starting with the Roadster sports car in 2008 (when Elon Musk became CEO), followed by successive models, designated X, Y and 3, achieving record sales such that the company became the world’s most valuable car company.

Tesla brought fresh thinking to bear on vehicle design, with a view to making best use of the limited driving range available from current batteries between recharging. The traditional car sales dealer network was cut out, as was conventional advertising and marketing, Musk relying instead on acquiring a large personal following of early adopters though social media and live presentations. This approach has proved very successful so far, but Chinese and Korean EV manufacturers are a growing challenge, while China has become by far the largest market for EV sales, where battery EVs currently comprise 29% of new car sales and plug-in hybrids a further 17%; corresponding figures for the UK are 22% and 40% respectively.

For legacy car manufacturers, design and manufacture of internal combustion engines has been a core competence, developed and executed in-house, with much else brought in from specialist equipment suppliers. Batteries are the most expensive component of an EV, whose performance is most crucial to the acceptability of the vehicle to purchasers. So the question for car manufacturers is whether to develop and make these in-house, or to partner with a specialised battery supplier, or to buy in batteries as a commodity, choosing the best available on the market. This strategic question is perhaps the most difficult, since the wrong decisions may have a major impact on sales. Another strategic question is whether to develop electric motors in-house, as does Tesla, or whether to buy in from specialist manufacturers.

One consideration is the desirability of locating battery production near to vehicle manufacture, given the weight batteries and the cost of moving them. Another is the possibility of advances in battery chemistry that offer better performance and/or lower cost. For instance, batteries based on lithium-iron-phosphate chemistry are lower cost but heavier than the hitherto standard lithium-nickel-manganese-cobalt formulation, whilst offering more limited range – less of a disadvantage in China where distances travelled are shorter than elsewhere. There is much effort underway to develop better batteries, yet only limited electrochemical theory to indicate likely directions for success, although much renown and commercial returns are to be gained if success is achieved. Also important is dependence on sourcing of key minerals, such as those mentioned above, although demand brings forth new supply, as ever.

Accordingly, difficult judgements are required as to where to locate battery development and manufacture in relation to car manufacture. Ten years ago, Tesla entered into a partnership with Japan’s Panasonic, a battery specialist, to build the first ‘gigafactory’ in Nevada, USA. In contrast, BYD, short for ‘Build Your Dreams’, founded in 1995 in China as a battery innovator, subsequently very successfully adding car and bus manufacture, has an integrated supply chain staring with lithium mining, and has now overtaken Tesla in global sales of EVs, focussing on lower price sub-premium markets – initially at least. There are a considerable number of Chinese start-ups that have entered a very competitive EV market, with downward pressure on prices – good for purchasers but challenging for the legacy manufactures such as VW that had been successful with petrol and diesel vehicles in the large Chinese market. Chinese manufacturers are now entering overseas markets, posing a threat to the European manufacturers, who have not developed integrated supply chains.

In response, as a trade protection measure, the EU recently imposed further tariffs of up to 45% on EVs imported from China, on top of existing 10% tariffs. This has been justified as a countermeasure against what the EU perceives as unfair competition, prompted by concerns that Chinese EV manufacturers have for years received substantial state subsidies, allowing them to produce vehicles at something like a 30-40% cost advantage as compared with European automakers. Chinese industrial policy support has enabled Chinese firms to build experience, reduce costs, scale up and push ahead on battery innovation. The EU tariffs are controversial since they may not be sufficient to exclude the lower cost Chinese vehicles from European markets, while possible retaliation may be counterproductive, particularly for European luxury car manufacturers selling profitably in China. There may also be increased likelihood that Chinese manufacturers would set up plants within EU countries to avoid the tariff. Indeed, BYD is already building a car plant in Hungary. For now, the UK has opted to stick to the existing 10% tariff, benefitting purchasers but possibly problematic for future trade negotiations with the EU.

The availability of low cost EVs from Chinese manufacturers puts pressure on competitors to extend their offering to include lower cost models. Tesla has just four cars in its model line-up, but none at low-cost entry level, which Elon Musk has justified by the expectation that it ‘is blindingly obvious at this point that [autonomy] is the future’, and announcing a two-seater autonomous Cybercab without steering wheel or pedals (pictured above), to be on sale before 2027. But this may be hoping for progress with vehicle automation that may not be fulfilled (see below), as well as a presumption that drivers would be prepared to forgo the satisfactions associated with personal car ownership.

Another possible role for governments is to support the construction of battery gigafactories, without which vehicle manufacturing may decline. The Biden administration has devoted substantial resources to boost US-based EV production. But the forthcoming Trump administration may cut such support, relying on tariffs to protect US manufacturers. The previous UK government published a battery strategy in November 2023, aiming (as usual) for Britain to be a ‘world leader’ and a ‘science superpower’. Two UK gigafactories have been announced so far, with government financial support, but a critical House of Commons committee report concluded that announced plans would satisfy little over half the capacity the nation needs by 2030. The failure of the Swedish Northvolt, Europe’s one-time battery champion, and before that of Britishvolt that planned to make batteries for EVs in Blyth, Northumberland, points up the risks involved in a major shift of technology.

The benefits of the switch to electric propulsion are environmental. The mobility to which we have become habituated in the built environment designed around it, that we have inherited, and which is very slow to change, means that the heavy lifting to decarbonise the transport system must depend on the expeditious switch of those vehicles deployed on it to electric propulsion. Incentives to achieve this can be contentious, however. A valuable recent report from the Resolution Foundation addresses equity aspects, arguing that, paradoxically, it has been justified for tax incentives to purchase EVs to target the richest fifth of households that are responsible for the majority of spending on new cars, who drive more, and whose new cars in due course feed the used car market for other buyers. But these incentives can be wound down now that capital costs are falling and the ZEV Mandate is in place to require manufacturers to ramp up EV sales.

However, a remaining impediment to EV purchase is that the cost of using a publicly-provided kerbside charger remains much higher than charging at home from the domestic electricity supply, an option not available to some 35% of British households. The public cost has increased by half since January 2023 despite wholesale electricity prices falling considerably, according to the Resolution Foundation, which estimates that the cost of driving an EV that is refuelled away from home is now double that of one charged at home (11.5 pence per mile compared with 5 pence per mile), amounting to a £425 difference each year based on average mileage. Regulation might now be needed to put a ceiling on the charges made by providers, analogous to the price cap imposed on domestic energy charges.

Vehicle automation 

There has been much enthusiasm in recent years – at least in technological, and some investment and governmental circles – to develop self-driving vehicles, also known as autonomous vehicles (AVs). The impetus has come largely from technology entrepreneurs who see the possibilities to earn large returns. Some politicians perceive AVs as powering industrial and economic growth. Traditional manufacturers are trying to keep up, to avoid loss of markets should the technology gain wide acceptance. However, the technical task has proved more challenging than anticipated, and thus slower to realise than predicted, and the prospects for widespread deployment of self-driving vehicles are far from clear, as indicated in a recent review. A variety of technological advances in combination may allow the human driver ultimately to be dispensed with, at least under specified conditions. The human is replaced by a robot driver – a robotic replacement for the control, navigation and safety functions exercised by an experienced and safe human driver.

There are a number of technological components that typically go to make the robot driver. The robot must sense its surroundings using video cameras, usually plus radar and often plus lidar, which uses the reflection of laser light to detect objects. It must know where it is located in relation to the features of the road network, requiring satnav location and high-definition three-dimensional digital maps, which need frequent updating. Fast software programming is required to fuse all collected images, using inexpensive hardware with minimum power requirements. But unlike a factory robot performing-well specified tasks in a well-defined space, the robot driver cannot be pre-programmed to deal with all situations that might arise, so the robot must learn on the job by utilising artificial intelligence to learn to cope with a wide range of circumstances.

While such a multicomponent approach to autonomous vehicle control is most generally employed, Tesla is restricting itself to cameras, to replicate the information available to a human driver. This reduces costs and avoids the need for digital maps, which eases wide deployment, although it is yet to be seen whether acceptable safety can be demonstrated – a general problem for all technological approaches.

There is extensive and ongoing development of automated technology both by new entrants to the road vehicle sector and by established manufacturers. There are broadly two approaches. An evolutionary approach adds individual features to progressively reduce the driving task, such as cruise control, lane keeping, lane changing and valet parking. These can be seen as further advances in the sequence of developments that have delivered established technologies such as automatic gearchange and automatic emergency braking. The potential problem is that as the tasks required of the driver are reduced, yet some remain (such as emergency intervention) and the driver’s attention may wander or may become occupied by unrelated tasks, with the risk that the human may not be able to respond sufficiently quickly to take control in circumstances where the robot cannot cope – such as sudden reduced visibility or a difficult-to-identify obstruction.

This problem of achieving a safe handover to the human driver when required has prompted an alternative approach – a step-change to automation in which the vehicle is designed not to need a human driver at all. If purpose-built, it may omit the steering wheel and other controls; where a conventional vehicle is adapted, conventional controls are normally redundant. Waymo, a subsidiary of the parent company of Google, has been the most advanced in developing vehicle automation, operating a driverless taxi service – a ‘robotaxi’ – initially in Phoenix (Arizona), subsequently in San Francisco, with Los Angeles and Austin (Texas) planned, all places where the weather is generally fine and the roads straight and wide. Yet there are reports of rapid progress by Chinese manufacturers in developing AVs for deployment in congested city centres. On the other hand, General Motors has just pulled out of the development of the Cruise self-driving taxi, attributing this to ‘the considerable time and resources that would be needed to scale the business.’ And earlier, Ford and VW had shut down a joint self-driving car venture.

More generally, the vision is that of equipping and permitting an autonomous vehicle to function without a driver within a defined geographical area where highway and traffic conditions are suitable. It would be more demanding to go beyond that to replace the human driver under all conditions, although this is the ultimate objective of the proponents of the technology.

However, the practical benefits of vehicle automation remain unclear. Proponents argue for safety benefits, especially in the United States where 41,000 people were killed in motor vehicle crashes in 2023. Given that human error and risky behaviour are responsible for 90% or more of fatalities, it would seem a reasonable expectation that robots could do better than fallible drivers. On the other hand, robots suffer from their own shortcomings, tending to be less effective at perceptions involving high variability or alternative interpretations. In particular, robots would find it difficult to engage in the kind of visual and body-signalled negotiation that occurs between human drivers to settle which gives way when space is tight or priority needs to be ceded to pedestrians, for example. Moreover, the driving performance of a robot would need to be very similar to that of a human driver to ensure public acceptability in mixed traffic. A robotic driver that proceeded particularly cautiously to meet safety requirements would be unattractive to purchasers of AVs. So, the robot driver would need to learn how to drive like a human.

Fatalities involving AVs, although rare, naturally attract attention. It seems likely that the public will expect an AV to perform substantially better than a human-driven car, but by how much is an important question. In any event, it will be difficult to demonstrate the safety performance of AVs in practice. For instance, in Britain there is one fatality per 140 million miles driven, so if AVs are to do better than a human driver, fatalities will be exceedingly rare events. One possible solution is to devise simulations of AV performance so that very large numbers of potential incidents could be studied, but then the problem is how to valid the simulation model as an adequate representation of real-world driving conditions. Whatever the approach, the authorities responsible for safety regulation are likely to have particular concern for public reaction to collisions and casualties involving AVs, both in anticipation and after the event. And the motor insurance companies will be concerned with who is to blame.

Another claimed benefit is that automation might increase the capacity of existing roads by allowing vehicles to move with shorter headways, that is, with a smaller distance between them than the recommended two-second ‘braking distance’ gap on fast roads. The more precise control exercised by a robot might also smooth traffic flows and allow the use of narrower lanes. However, such increases in capacity seem likely to be possible only on roads dedicated to AVs since the presence of conventional vehicles, not to mention cyclists and pedestrians, would require standard spacing to be maintained. In any event, any increase in capacity would be expected to attract additional traffic, so that congestion relief would not be expected. Automation that allowed an increase in road capacity might be of interest to a road authority, but not to individual vehicle owners would bearing the cost of the necessary technology.

There are other potential (and possibly unforeseen) consequences of vehicle automation.  Because AVs would be capable of operating empty, for example when returning to base after dropping off the occupant, they could add to traffic and hence to congestion. Conventional taxis operate without a passenger while seeking a fare, of course, but privately owned vehicles without occupants would be a new source of traffic and may require regulation if congestion is not to worsen. There is also the problem of AVs getting stuck in the traffic flow at critical points in the network or ‘trapped’ in odd places (as has already been happening) and not able to move to safe pausing places, as would a traditionally-driven car.

The prospects for widespread vehicle automation on existing roads with mixed traffic therefore seem very uncertain. Much will depend on whether users see the benefits outweighing the costs. The benefits for private owners of AVs are improved journey quality and the chance to carry out other tasks while in the move. This could allow greater distances to be travelled, but that would increase traffic, so no useful increase in speed or in access seem likely. For taxi operators, the benefits would be saving the labour cost of drivers. A more ‘visionary’ possibility is that of widespread shared use of individually owned AVs, taking advantage of the ability to summons such a vehicle when needed, and avoiding have a privately owned vehicle parked for 95% of the time – a concept advocated by Elon Musk. This could offer efficiency benefits, spreading capital costs over more miles travelled. Yet the experience of individual car ownership is deeply ingrained, both for the certainty of having this means of mobility available when needed and because of the good feelings associated with ownership of an attractive consumer product.

Whatever the type of ownership, the costs of automation comprise the equipment on the vehicle plus remote supervisory back-up in case of unexpected events. There are also the large research and development costs incurred to deliver safe, effective and attractive vehicles – likely to be of a magnitude such that acceptable returns could ultimately only be made through sales to the mass market of private purchasers. In the meantime, providers of robotic taxis and public service vehicles may benefit from the technology, but only if the additional costs of automation are less than the costs of employing a driver that may be dispensed with – by no means a forgone conclusion.

The UK has enacted legislation to regulate autonomous vehicles, implementing the recommendations of a very thorough analysis by the Law Commission. While creating a clear framework to govern responsibilities for vehicles when in driverless mode, such responsibilities will impose likely significant costs of oversight on manufacturers who sell AVs to private owners and on robotaxi operators. It would not be surprising if the human taxi driver were to be the lower cost option, as well as generating less public anxiety in the event of mishap.

What are the priorities – EVs or AVs?

Both EV and AV technologies contrast sharply with the transport innovations of the previous two centuries  – the steam railway, the internal combustion engine for road vehicles, and modern aircraft – each of which took advantage of the energy of fossil fuels to effect a step change increase in the speed of travel, the benefits of which people took in the form of increased access to people and places, activities and services, with the greater opportunities for human interactions and choices that this made possible. Likewise for the modern bicycle, a later nineteenth century invention that harnessed human effort. But electric propulsion yields no step change increase in speed, and so not in access, nor does it seem likely that vehicle automation will yield such an outcome either. The case for deploying EVs is to reduce the transport sector’s carbon emissions, a key strategic objective. The case for AVs is to improve the quality of the journey, as perceived by individual purchasers, or to reduce operating cost of robotaxis if that proves feasible. Evidently, EVs are much more important than AVs as regards policy concerns about climate change.

Accordingly, competition amongst auto manufacturers to introduce new and better EVs is very desirable, regardless of their origin. Uptake by purchasers is constrained by anxieties about charging possibilities – the concern about ‘range anxiety’ – the least for those able to use home chargers in the driveway, but still a deterrent where long distance trips are contemplated. In the long run, provision of public charging points would be a commercial matter, as are roadside filling stations, but in the short run we have a chicken-and-egg problem that justifies government financial support for the provision of more retail charging outlets, as well as regulatory initiatives to speed the enlargement of the electricity transmission and distribution system.

The new Labour government has issued a consultation paper on industrial strategy. Eight growth sectors are identified, including advanced manufacturing, in which context it is claimed that up to 56 gigawatt hours of electric vehicle battery manufacturing capacity is planned for the UK so far, and that we are on our way to reaching the 2030 capacity requirements expected by the sector. The Chancellor of the Exchequer’s Budget Statement of 30 October allocated over £2 billion up to 2030, to support the zero-emissions vehicle manufacturing sector and supply chain.

The previous Conservative government was very supportive of driving forward vehicle automation, enacting legislation to support that aim, emphasising the benefits to the industrial economy rather than the transport system. However, there was no mention of support for AVs in the new Chancellor’s Budget Statement – a reasonable decision, in my view. There has been little development of the technology in Britain to the point of on-road deployment without a safety driver, in contrast to the position in the US and China. Moreover, the lack of UK-owned car manufacturers does not suggest that this technology is likely to be first rolled out here at scale, even though there are UK tech enterprises gaining investor support, notably Wayve, which is applying AI to self-driving in on-road trials and hopes to partner with vehicle manufacturers.

Vehicle automation is progressing incrementally, yet the goal of widespread driverless operations across the whole road network still seems elusive, while it remains to be seen whether the benefits to road users are sufficient to justify the higher capital and operating costs involved. The benefits of vehicle automation for both industrial and transport policy do not seem to be great. It is conceivable that public transport or freight vehicles could operate in driverless mode in some circumstances – at low speed on campuses, in dedicated lanes or roadways, or on set routes on which hazards are minimised. But the economic case, based on the costs savings of a human driver, may be difficult to justify.

The top technology priority for transport policy has to be the switch to electric propulsion of road transport, to which UK and European legacy manufacturers are giving high urgency. Yet establishing viable product ranges competitive with Chinese providers is proving difficult. Besides, the possible emergence of acceptable and attractive automation raises a strategic question of priorities for manufacturers beyond the switch to EVs, bearing in mind Tesla’s twin track development of an electric, automated robotaxi, as well as the progress being made by the Chinese auto industry in combining electric propulsion with automation. Who would bet against Elon Musk, given his record in pioneering EVs, reusable rockets and ubiquitous satellite communications? And who would bet against the Chinese in any technology that the state designated as strategic.

The current pace of digital and electrochemical technological change is fast in comparison with that of the auto manufacturing business whose timescales for new model development are long. In these circumstances, it is hard to have confidence that good decisions are being made by those with power to influence outcomes. Yet decisions cannot be avoided. 

The above blog was the basis of commentary published in Local Transport Today on 18 December 2024.

The previous Conservative government had initially been supportive of Low Traffic Neighbourhoods (LTNs), consistent with its positive attitude to promoting active travel. But before the general election of July 2024, it swerved, recognising the unpopularity of some schemes, seen by some as anti-motorist. In my own neighbourhood, the local authority engaged residents on a proposed LTN scheme last summer, which generated a good deal of opposition from those that thought they would be adversely affected, and a petition of more than 3000 signatures. The environmental scrutiny committee of the local authority held a meeting this week at which deputations could express a view. I had previously prepared a note on the topic, and had the opportunity to make a short oral presentation. The substance of my note follows, omitting specific references to locations in the neighbourhood.

The previous government commissioned a review of the evidence of the impact of LTN schemes, which reported in March 2024. A total of 99 schemes were identified, of which 82% remained in place and 18% had been removed. The main conclusions derived from all the evidence collected were that LTN’s are effective in reducing traffic on internal roads, although outcomes for boundary roads were mixed; air quality on internal roads has improved, but that on boundary roads varied; and impact on walking and cycling has been mixed.

Transport for London has summarised experience of LTNs in London, concluding that the evidence to date consistently shows that they are having a positive impact on the lives of people living and working in London, although the impacts take time to develop.

There have been academic studies, notably Thomas and Aldred’s review of 46 London LTNs for which monitoring data was available, finding substantial falls in traffic within schemes, but on boundary roads little change in the overall average traffic but substantial variation across schemes.

In general terms, it would be desirable to reduce through traffic within the nighbourhood, the magnitude of which seems to have been increasing in recent years, likely due in part to the wide use by drivers of satnav that indicates the fastest routes, often on smaller roads that are best suited to walking and cycling.

The evidence presented in support of the proposed LTN includes historic traffic count data for many of the roads. But no information is available on the origins, destinations and purposes of trips, which means that traffic modelling of likely outcomes of the scheme is not possible. Gathering information on trip origins, destinations and purposes requires considerable effort and expense, employing household and roadside surveys, GPS and mobile phone data, and in general would only be attempted for proposed major road schemes, not for proposed LTNs. So one can only speculate about likely changes to traffic flows in a specific case. But because implementing the LTN does not involve major and irreversible road works, a trial-and-error approach is justified, encouraged by the findings of the 80% success rate noted above and by the withdrawal of 20% which failed to meet expectations.

Nevertheless, some questions about likely changed traffic flows may be posed. For instance, judging by the difference in flows at the morning peak between school term time and holidays, there is a fair amount of ‘school run’ traffic. This seems likely to be mainly the consequence of residents dropping off children at schools outside the neighbourhood, as well as non-residents driving children to the secondary schools within the neighbourhood. But without knowing which schools are the destinations, it is hard to estimate to what extent such trips would persist with the implementation of the LTN (the alternative being more children making their own way), but taking more time and covering greater distances, so generating more traffic to offset the reduction in through traffic having no business in the neighbourhood.

In the absence of traffic modelling of likely flows with the LTN in place, we can only pose questions about the key outcomes:

  • The net overall traffic reduction: the extent to which the reduction in through traffic is offset by increased distances travelled to addresses in the neighbourhood by residents, delivery vehicles, taxis etc, as well as increased distances travelled by residents out of the LTN.
  • The extent of diversion to boundary roads.
  • The extent of ‘disappearance’ of traffic.

‘Disappearance’ refers to the way in which traffic reduces in response to some impediment to flow. Time is always a constraint on travel. Impediments such as congestion or, in the present case, the need to travel greater distances, prompt some drivers to make alternative choices where feasible: an alternative route where delays are less, an alternative mode of travel, an alternative time of departure, an alternative destination (for instance for shopping), or not to travel at all (such as ordering goods online). There is good evidence for the reality of traffic disappearing, although the extent depends on the nature of the location. The availability of good public transport is helpful. One possible source of traffic disappearance would be if parents bring forward the point in time when they cease to take their children to school by car, letting them travel independently by public transport or on foot.

Entry of vehicles into the LTN is intended to be controlled by a mix of fixed barriers and camera-enforced controls, both forms open to use by cyclists and pedestrians. Given the inevitable uncertainties about travel volumes, both for individual roads, internal and boundary, and in aggregate, two varient approaches are worth considering. First, to exempt residents from penalty charges for passing camera-enforced traffic filters. This would allow residents to take the more direct route, reducing traffic in the neighbourhood, while blocking through traffic. Second, the camera-enforced traffic filters might operate only at peak times, as for Healthy School Streets, preventing the bulk of through traffic.

It would be usual to implement the LTN for a trial period before a decision on firm plans. It is common with such schemes to initially implement by means of an Experimental Traffic Order, which is limited to a period of 18 months while the effects are monitored and assessed, after which decisions are made whether or not to continue with the changes on a permanent basis. A commitment by the local authority to a reliable means to assess local opinion would be desirable, based on data from monitored traffic flows before and after scheme implementation. It is worth recalling that the local Neighbourhood Plan was adopted by the local authority in 2020 following a local referendum.

The engagement phase for this particular scheme has concluded. I expect the next phase will be a formal consultation on a modified plan that responds to the concerns expressed, as far as feasible. I also expected that the outcome of that will be a trial implementation, which is likely to show that some of the concerns will not be borne out in practice. A key question will be whether there is a significant increase in traffic on the boundary roads. If not, I would expected the LTN to be made permanent.

In general, transport in the UK has been regarded as a well-regulated sector. It is not surprising, given the obvious potential for public harm, and the high profile of any errant behaviour or system failures. Vehicles, drivers, infrastructure, and service provision by operators are all subject to safety and customer protection regimes. But technology and business practice move on, generating new issues to be addressed. Generally, this happens on a rather piecemeal basis when new modes, technologies, or commercial models emerge, but not always then.

Accordingly, under the Boris Johnson government, the Department for Transport launched its Future of Transport Regulatory Review in 2020 in the form of a call for evidence, initially focused on three areas: micromobilty; flexible bus services; and Mobility as a Service. Other topics that have been considered under this broad initiative included the future of flight, and modernising road vehicle standards. There has also been a look at ‘regulatory sandboxes’ as a means to introduce temporary or specific place-based regulatory flexibilities to support innovation. Yet addressing such topics ad hoc seems to have so far yielded little in the way of useful regulatory advance in any of these fields, let alone others of concern such as secure digital payment systems, customer data protection, and standards of information provision, for example.

One area that has been subject to full consideration is the regulation of automated road vehicles (AVs), an area where the last government seemed to believe there to be a major new industrial development and employment opportunity. The Law Commission was asked to recommend a regime to govern responsibilities when vehicles are operating in driverless mode, whether as ‘robotaxis’ or individually owned vehicles. The outcome was the Automated Vehicles Act 2024, which had broad political support. There is now in place a comprehensive legal framework that developers, operators and insurers of AVs might see as helpful in making clear their legal responsibilities, which, however, might be seen as quite onerous compared with arrangements in countries where the main development of the technology is taking place, the US and China in particular. UK developers of AVs are limited in number and their commercial prospects are unclear.

To be sure, the regulatory regime being put in place for AVs is forward looking and intended to encourage innovation. But the implications for the wider transport system and the management of the road network as a whole, particularly in urban areas, are consequential matters that also need careful consideration, a topic recently reviewed by the International Transport Forum and the subject of an exploratory project report by the National Infrastructure Commission.

Another fast-moving technological development area is aviation. Here a comprehensive sectoral regime operated by the Civil Aviation Authority is well established to oversee safety, security, the efficient use of airspace for maximum public benefit, and to protect the consumer interest. The CAA has set up an ‘innovation hub’, the purpose of which is to create an environment where innovation in aviation can develop in line with the CAA principles. These include ‘pilotless‘ planes and drones. A recent review endorsed the view that CAA is a world class regulator that is fit for purpose, delivering high quality services to the aviation and aerospace industry and the consumer. Moreover, the CAA and DfT are consulting on the creation of a new UK Airspace Design Service that would act as a single guiding mind for modernising the design of UK airspace, exemplifying the CAA’s proactive approach to innovation.

A further sector-wide regulator is the Office of Rail and Road, which originally was solely charged with regulatory oversight of railways, including holding Network Rail to account for stewardship of its network, its funding, as well as protecting the consumer interest in respect of services provided by the train operating companies. The ORR carried out a consultation in 2015-16 on its approach to innovation, following a prompt from the government. The ORR has taken the view that innovation is led by the rail industry and where appropriate it would be supported by the overall regulatory framework, including the duty to promote improvements in railway service performance and promote efficiency and economy on the part of providers of railway services. So, compared with the CAA, the ORR’s approach is relatively passive.

Since 2014, the ORR also has some oversight of roads, but this is limited to the engineering performance and efficiency of National Highways in England in respect of its network, not to other roads. The ORR’s remit does not allow it to address the benefits to road users of new road investments – whether the outturn from investment in new road capacity meets expectations – nor whether the strategic road network is being efficiently utilised (unlike the CAA’s concern with the efficient use of airspace). Again, there is a lack of intention actively to foster technological innovation for the strategic road network, or to analyse and prioritise the optimal use of capacity, and identify where enhancement is most justified.

For road vehicles more generally, there are important examples of regulatory approaches that both drive and support technological innovation. Tackling the harms from tailpipe emissions of petrol and diesel enginned vehicles has been effected by regulations within the portfolio of the Department for Transport that have driven down emissions of air pollutants and by the ZEV Mandate, a legal requirement for a minimum percentage of each manufacturer’s new car and van sales to be zero-emission each year.  Regulations made by local authorities to create urban clean air zones (in London known as the Ultra Low Emission Zone) also help incentivise the switch to electric propulsion, a once-in-a-century transport technology innovation. While the propulsion systems and physical impacts of individual classes of vehicles are a DfT matter, concern for overall emissions and air pollution lie elsewhere – with the Department of Environment, Food and Rural Affairs (Defra) and Department for Energy Security and Net Zero (DESNZ).

When it comes to new modes of travel, the Department for Transport again seems to be following rather than leading, with actions in fits and starts, for example in making regulations allowing trials of rental e-scooters to be fast tracked and expanded in response to proposals from local authorities. The intention is to understand usage, safety, and environmental impacts, and to explore changing travel patterns since the coronavirus pandemic and as e-scooters become more embedded in public life. Only e-scooters participating in official rental trials may be used legally on roads. It is expected that a decision will be made in due course about legalisation of e-scooters as a vehicle class, and about the appropriate regulatory regime, which may include a requirement to park rental e-scooters in prescribed bays. E-bikes are already legal and treated as ordinary bicycles if of limited power, but the problem of inappropriately parked dockless rental e-bikes prompts complaints and pressure to regulate.

In contrast to the supportive approach to e-scooters, and a permissive approach to e-bikes, as innovative mobility technologies, there has been inaction in several other significant areas. This includes updating the historic taxi and private hire legal regime, with minimal recognition by the authorities of the merits of ride hailing as an innovative means of summoning a taxi, exemplified by Uber’s struggles to get acceptance in London. This involved a number of court cases, which found in favour of Uber, while the company lost some other cases concerned with the employment status of drivers, which nevertheless has not seemed to impact on the provision of the service. Uber’s digital request and booking/payment system has proved very popular with users as a better means of getting a taxi compared with licenced black cabs or conventional private hire vehicles, as well as being sufficiently attractive to drivers so as to offer customers an acceptable level of service. But this outcome was no thanks to a taxi regulatory regime having a remit to foster innovation. On the contrary, taxi regulation is historic, not modernised for the digital age, rightly concerned with the protection of customers, less defensibly having the effect of protecting the trade of established black cab drivers. There is a marked contrast between this reluctance to welcome innovative approaches to taxi services and the progressive stance towards automated vehicles, including robotaxis.

In terms of road usage, beyond the urban areas where e-scooters and ride hailing taxis operate, regulation of the inter-urban system roads is confined to vehicle and driving licence holding, vehicle type approval and performance – handled by a number of specific agencies like DVLA and DSA – with speed limits and other rules of the road embodied in the Highway Code – an historic regime that has not generally recognised advances in innovative technologies.

One technological innovation that has been widely adopted is digital navigation, applicable to all travel modes to replace conventional maps. In the road context, this is generally known as satnav and is offered by a number of providers including Google Maps and Waze via free-to-use smartphone apps, and others who provide input to equipment installed by vehicle manufacturers. A key element of many of these offerings is to indicate the fastest route in the light of prevailing traffic conditions. Digital navigation is changing the way drivers use the road network in three main ways: local users are attracted to new capacity on major roads, pre-empting the additional capacity intended for longer distance business users and so weakening the economic case for the investment; longer distance users can divert to local roads that offer faster journeys than on congested major routes, roads that are well suited to active travel; and predictive journey time information allows more efficient use of the network.

At present, provision of digital navigation is a free-for-all, funded by sales of direction-finding to businesses that wish to attract clients to their premises, as for Google Maps; or by the sale of services to vehicle manufacturers that fit navigation as original equipment, as for TomTom. Road authorities generally seem to be paying little if any attention to these developments. Yet there are opportunities being overlooked to make better use of the road network, both urban and inter-urban, including buses services.

Curiously, legislation has long been in place to allow providers of digital navigation to be regulated. This dates back to 1989 and requires what were then termed ‘dynamic route guidance systems’ that take account of traffic conditions to be licensed by the government. The intention was to facilitate the introduction of a pilot route guidance system, known as ‘Autoguide’, that had been developed by the government’s Transport and Road Research Laboratory and required roadside equipment to be installed – a good example of forward-looking regulation to support innovation. The licence could include conditions concerning the roads that should not be included in the route guidance, the provision to road authorities of information on traffic conditions, as well as the right to install roadside equipment. In the event, the Autoguide pilot did not proceed, due, I suspect, to the limited computing power available at that time. Nevertheless, the legislation has remained on the statute book although no licences have been applied for or granted.

The possibility of achieving more efficient use of the road network through provision of better information about traffic conditions to both road users and road authorities was recognised early on by John Wardrop, a traffic analyst at the then Road Research Laboratory, in a seminal paper published in 1952. He postulated two equilibria. The first states that, under equilibrium conditions, traffic arranges itself in congested networks in such a way that no vehicle can reduce its costs (time and money costs) by switching routes. For this to happen in practice, drivers would need to have perfect knowledge of all feasible routes and travel times. Digital navigation may be seen as improving such knowledge, thus enhancing network efficiency, yet with a number of independent providers that may offer conflicting advice, it is hard to assess to what extent increased efficiency is being achieved.

Wardrop’s first equilibrium assumes that road users make decisions without regard to the impact their choices may have on others – a ‘selfish’ equilibrium. According to his postulated second equilibrium, the average journey time would be at a (lesser) minimum if all users behave cooperatively in choosing their routes to ensure the most efficient use of the whole system. This would be the case if an omnipotent central authority could command them all which routes to take. Traffic flows satisfying Wardrop’s second equilibrium are generally deemed system-optimal, and the loss of efficiency from this to the selfish equilibrium is an example of what is known as ‘the price of anarchy’.

Economists argue that a more socially optimal outcome could be achieved if the costs imposed by the marginal road user on others, by adding to congestion, could be internalised by a congestion charge, thus modifying behaviour by reducing demand through higher vehicle operation costs. However, implementing road pricing is difficult in practice, and there are issues of equity, so a question worthy of investigation is to what extent a more socially optimal outcome could be achieved through flexing the routing advice offered by providers of digital navigation – ‘nudging’, not compulsion

The likelihood that improved operational efficiency could be achieved through digital navigation is suggested by the wide use of such routing and navigation systems by the competitive road freight sector. Everyday experience of online shopping indicates the use made by logistics businesses of digital technologies to manage, track and predict flows of goods, often offering delivery time slots of two hours or less, all done algorithmically. This points to techniques to achieve operational efficiency on congested road networks that might be extended to the generality of traffic in a way that could be far more cost effective and less carbon generating than civil engineering technologies.

The competing providers of digital navigation services are generally uncommunicative about their operations, while highway authorities appear to show no interest in the impact of this technology on the functioning of the road networks for which they are responsible. One kind of opportunity for mutual benefit would be when the network is under stress, for instance on the occasion of major incidents, peak holiday flows, bad weather and the like. It is probable, and certainly worth further investigation, that coordination between highway authorities and digital navigation providers could make better use of available capacity. There is also the possibility of improving operations at normal times, including avoiding routing through traffic via unsuitable minor roads. There is therefore likely to be scope for coordination that would improve outcomes for road users. This might be through the parties acting voluntarily for mutual benefit, or through the updating and implementation of the 1989 regulatory regime.

Although, by and large, the transport sector is functionally regulated to avoid calamity, there are obvious gaps that could usefully be filled to the benefit of users and to give innovators a sound basis upon which to progress their new ideas – or at least try them out with appropriate dispensation. This is particularly the situation in respect of the operation of the road network. As well as concern for safety and customer protection, all regulators should have a remit to encourage innovation that offers user benefits, since making effective use of existing infrastructure is preferable to creating new capacity, given the need to achieve the Net Zero climate change objective.

The new Labour government has set up a Regulatory Innovation Office, with the aims of supporting regulators to update regulation, speeding up approvals, ensuring different regulatory bodies work together smoothly, informing the government of regulatory barriers to innovation, and setting priorities for regulators which align with the government’s broader ambitions. This is an ambitious and potentially extensive agenda. Yet it will be disappointing if the emphasis solely on novel and exciting new technologies, a possibility suggested by one initial topic, the role of drones as a form of connected and autonomous vehicle technology – surely a rather niche market. In contrast, there is much scope for encouraging innovative approaches in the mainstream emerging transport technologies, where the new Office could hopefully play an influential role.

This blog post is the basis for an article that was published in Local Transport Today 0f 31 October 2024.

My new book, titled ‘Travel Behaviour Reconsidered in an Era of Decarbonisation’, brings together arguments and evidence that I have discussed briefly in my commentary columns in Local Transport Today and in previous books intended for non-specialists. This book, aimed mainly at professionals and academics, is fully detailed, evidenced and referenced, yet concise and (I hope) cogent, the core of which is a critique of orthodox transport economic analysis and modelling, plus proposals for fresh approaches. It is published by the UCL Press, part of my own institution, an academic open access publisher launched in 2015, that makes copies of its books free to download as PDFs and claims more than 10 million downloads so far. In this blog post I will outline the main themes of the book, as a trailer to encourage readers to access the full text.

I argue that the need to reconsider travel behaviour and its analysis is two-fold. First, decarbonising travel could be achieved both by new technology and by altering behaviour so that we make less use of the car. The question for consideration is whether such behaviour change is feasible in practice on a scale that would make a useful contribution.

Second, I argue that there is a need to reconsider the economic analysis of transport investment so that this reflects the observed travel behaviour of real people in the real world, as opposed to assumed behaviour of utility-maximisers functioning within constrained analytical frameworks, the orthodox practice.

Behaviour change

To set the scene, the first chapter of the book outlines the pattern of travel on Britain, largely based on findings of the National Travel Survey prior to the pandemic. (UK data is particularly extensive, but I refer to other countries where possible.) The main feature, of course, is the dominance of car travel, which brings with it a variety of problems familiar the LTT readers. Yet the attractions of the car tend to be underestimated by those who hope for a shift to public transport and active travel. The car provides convenient door to door travel over short to medium distances where road traffic congestion does not cause excessive delays and parking is available at both ends of the trip. These conditions may not be satisfied in city centres, where public transport can be provided most economically and where catchment areas, whether for schools or supermarkets, are tighter, making active travel more feasible. But beyond city centres – in the suburbs, towns and rural areas – alternative to the car are much less attractive and mode shift much more difficult to achieve.

Yet the car is not attractive just for its utility; there are also ‘feel good’ factors that prompt car ownership and car-dependent lifestyles. Witness that cars are parked for 95% of the time, a good economic argument for car sharing, but conversely an indication of the value placed on private ownership. Witness also the growth ownership of SUVs, not least in urban areas where there is little practical need for a large 4×4 in place of a traditional smaller hatchback. The motor manufacturers are naturally focused on satisfying such feelings; and governments are supportive of auto industries for reasons of industrial and employment policies.

In the third chapter of my new book, I outline the important consequences of the coronavirus pandemic, a ‘natural experiment’ that showed how digital access could substitute for physical access under ‘lockdown’. Yet once the restrictions were lifted, car use returned quickly to pre-pandemic levels, consistent with the attractions of the car for gaining physical access to people and places, activities and services.

Chapter 6 discusses the routes to transport decarbonisation. For surface transport, electric propulsion is by far the most important means, though the equivalent in aviation is much more difficult. Some analysts and policy makers argue for a substantial reduction in car use as well, for instance by 20% as soon as 2030. But because of the attractions of the car, and given the built environment we have inherited within which trip origins and destinations very largely arise, any such reduction reflects much wishful thinking. The best prospects are in city centres where rail in all its forms provides speedy and reliable travel compared with cars, buses and taxis on congested roads. But urban rail is costly and takes a long time to build. Cycling infrastructure is much cheaper and quicker to implement, but largely attracts people from public transport, not from their cars.

So the prospects seem quite limited for changing travel behaviour and reducing car use on a scale that would make a useful contribution to decarbonisation objectives. How did we get to this state?

Changing travel trends

The historic trends in travel behaviour, the successive changes that have occurred, and their implication for future demand, are at the heart of what the new book explores. The evidence presented in the second chapter suggests four eras of travel: first, early man came out of Africa to populate the habitable earth, walking for 3-4 hours a day, covering around 3000-4000 miles on average, hunting and gathering. Then, starting 12,000 years ago, settled farming communities came into being, when average daily travel time fell to about an hour a day, covering about 1000 miles a year at walking speed (horse drawn vehicles on poor roads were not much faster).

The third era began in 1830 with the opening of the first passenger railway, between Manchester and Liverpool, utilising the energy of coal to travel faster than walking pace. Oil in the twentieth century permitted mass mobility through the internal combustion engine employed for road vehicle propulsion, as well as air travel. And the modern bicycle harnessed human power for local trips at faster than walking pace. According to the National Travel Survey, the average distance travelled in Britain increased to reach about 7000 miles per person per year by surface modes by the end of the twentieth century, with average travel time invariant at an hour a day. But then growth ceased, in part the result of exhausting the scope for faster travel through refinement of established technologies. This was the beginning of the fourth era of travel, that driven by the need for decarbonisation.

Each of these past innovations in transport technology based on fossil fuel energy led to a step-change increase in the speed of travel, and in turn to increased distance traversed in the long-run invariant hour a day of daily travel. Hence the benefits of faster travel were taken in the form of greater access to people and places, employment, services and activities, to family and friends, with the enhanced opportunities and choices that improve our quality of life.

In contrast, the new transport technologies seem unlikely to result in increases in speed of travel or of access. Electric propulsion is important for decarbonisation but does not increase the speed of travel. Digital platforms, exemplified by the access readily provided to car travel by the likes of Uber, and digital navigation, known in the road context as satnav, improve the quality of the journey without increasing speed. And automated vehicles on roads shared with conventional vehicles seem unlikely to permit faster trips. So these, the main new technologies, will not increase access benefits to users of transport networks.

A second reason why the growth of average daily distance travelled ceased to increase at the turn of the century, is evidence that those with the availability of a car in the household or good public transport services have arguably adequate levels of access, choices and opportunities, such that there is no need to travel further. Hence demand can be said to be saturated, a general feature of mature markets, and with no reason why travel should be an exception. However, travel to permit access has two distinct characteristics. First, improved access to any given class of destination is subject to diminishing returns, a standard economic concept. And second, access increases with (up to) the square of the speed of travel, reflecting elementary geometry. The combination implies that per capita travel demand for the purposes of access may be expected to saturate, consistent with the findings of the National Travel Survey and other sources.

While per capita travel has ceased to grow, the UK population is increasing, which requires consideration of how this may propel travel demand growth. Much would depend on where the growing population would be housed: new homes on greenfield sites would increase car use, whereas accommodating population growth within existing urban areas would point towards improvement of public transport services to meet the associated transport needs. The scale and location of new homes is currently a major issue of national policy, yet to be settled.

So the fourth era of travel is characterised both by the lack of new technologies to travel faster, and by substantial travel demand saturation, both helpful to implement transport decarbonisation. Yet population growth accommodated on greenfield sites is unhelpful. Overall, the scope for a significant reduction in travel demand seems quite limited.

Appraisal and modelling reconsidered

The second core theme of my book – decision-making processes for transport investment – leads to a fairly detailed critique of conventional transport economic appraisal which is based on the supposition that the saving of travel time is the main benefit of investment in new capacity. My conclusion is that it has not been possible to achieve a self-consistent methodology in this territory even after some sixty years of effort. One consequence is a mismatch between the policy objectives of many high-profile investments and the conventional estimation of economic benefits, which is therefore suitably massaged to align with the policy.

At the same time, there has been growing general recognition that the main benefit of investment that allows faster travel is increased access. However, attributing monetary value to access has proved difficult conceptually, and has not been successfully developed into a methodology for practical application. Besides, as noted above, travel demand for the purposes of gaining access is subject to saturation, quite unlike demand based on the supposition of time saving, which means that the latter cannot be a proxy for the former.

Identifying the benefits of investment as enhanced access creates problems for transport modelling, another issue I explore in some depth in the new book. Transport models to justify major investments typically comprise two parts: a variable demand multimodal traffic model, the outputs of which are inputs to an economic model that allows estimation of monetary benefits, comparing the with- and without-investment cases, and hence yielding the benefit-cost ratio, important for the decision to invest. Yet benefit in the form of increased access cannot be accommodated by the economic model as it exists, on account of the assumption of transport economists that time savings are the main benefit. This therefore requires the traffic modellers to constrain model outputs to a counterfactual case in which travel time is saved, rather than used to travel further for greater access, disregarding the increased vehicle-mile-related externalities and land use change that arise in reality. So transport modelling as currently practiced does not provide a secure basis for the estimation of investment benefits, nor of carbon and other externalities.

Fresh approaches

Pulling all these threads together, the final chapter of my book suggests some fresh approaches to travel analysis and transport policy, to respond to the methodological shortcomings of conventional appraisal and modelling that I identify, and to the need to make progress towards the Net Zero objective. I suggest a presumption that Britain has a mature transport system comprising the road and rail networks, consistent with travel demand saturation as discussed above. This is already the case for urban roads, where, in the last century, investment in increased capacity in the form of both new (often elevated) highways and enlarged carriageway for vehicles took place in response to growing car ownership; whereas more recently the trend has been to recover such capacity for active travel and prioritised bus routes. Demand for vehicle travel on urban roads must now be managed within constrained capacity.

There is a good argument for treating the interurban road network as mature, so not aiming to invest to increase capacity generally, hitherto justified by notional travel time savings. There may be benefits from particular investments associated with land use change; for instance, were a third runway at Heathrow airport to be built, investment in surface transport infrastructure would be needed to cope with increased passenger numbers, the resource implications of which should form part of the cost of the project as a whole.

More generally, location-specific road investment to make land accessible for development could be justified where the decision to develop is made jointly by planners, developers and transport authorities and where the developer contributes to the cost of the infrastructure. The case would be based more on commercial considerations than on orthodox welfare economics, although carbon emissions and other externalities should be taken into account.

Cessation of investment in a national road construction programme would be a big shift of policy politically, although this is what the Welsh government decided two years ago. But there is still widespread support for road investment among most politicians, national and local, the latter because the funds provided by central government are seen as ‘free money’. It is widely supposed that increasing road capacity reduces congestion, improves connectivity and boosts economic growth, although the basis for this supposition is tenuous. And of course, the construction industry and the consultancies that benefit from the funds that flow are also supportive. Nevertheless, there is a strong case for a switch in effort from costly investment in new civil engineering structures to making best use of the physical infrastructure we have. Economic analysis and modelling would then focus on the efficient management and use of the network, closely linked to the operational analysis of the road network in real time, a topic that has been neglected hitherto. To do this we now have the opportunity to take advantage of digital technologies that are already in wide use and are both scalable and relatively low cost.

Transport economic analysis has focussed on individual projects. In contrast, it has always been difficult to articulate an economically persuasive strategic case for a programme of transport investment. Regarding the transport system as substantially mature changes the main challenge from justifying a collection of investment projects to reconciling transport operations with the Net Zero objective.

The key elements of a strategy, whether of a particular sector or of transport provision as a whole, are:

  • the switch to zero-emission vehicles for surface transport;
  • employment of digital technologies to optimise network operations;
  • and financial support for public transport.

Alongside these, any investment in new capacity should now be specifically justified case by case to support economic development, such decisions being taken jointly with planners and developers, and schemes funded in part by the developers, as beneficiaries.

Active travel is not included in my key elements of strategy, although it is a good thing in many respects, including health and environmental benefits – I myself am a cyclist. But I see limited scope for getting people out of cars onto bikes. Copenhagen is a city famous for cycling, but car mode share is only slightly less than in London, while public transport is half that in London. So you can get people off buses onto bikes, but harder to get them out of cars, even in a small, flat city with excellent cycling infrastructure and a strong cycling culture.

One reason is that in Britain 80% of carbon emissions from car journeys arise from trip of more than 5 miles, and 95% from trips of more than 2 miles, so only limited opportunity to get switch to cycling and walking respectively. I don’t therefore see promotion of active travel as a central
element of a national transport strategy, although in cities with crowded public transport it may have more attractions, as in London, albeit with some loss of farebox revenue.

POSTSCRIPT

The new government’s policies: do they meet the need?

The manuscript of my book was completed before the General Election, which has led to a new focus on the basis of transport decision-making and the sources and allocation of funding. The new Labour Chancellor Rachel Reeves soon cancelled the proposed Arundel Bypass on the A27 and the tunnel adjacent to Stonehenge on the A303, as well as some minor rail schemes, laying the blame at the budget deficit.

Louise Haigh, the new Transport Secretary, has meanwhile been required to undertake a review of £800m of unfunded commitments in her department and a basis of prioritisation of projects, suggesting shortcomings in its system of controls. A new Office of Value for Money is to be established to identify areas where the government can reduce or stop such problems or improve the value of spending.

The government also intends to establish a National Infrastructure and Service Transformation Authority (NISTA), comprising the National Infrastructure Commission and the Infrastructure and Projects Authority, to drive more effective delivery of infrastructure across the country and support a 10-year infrastructure strategy. A seasoned transport and railway professional, Lord Hendy, has been given the rail policy brief, and a junior minister at the Department for Transport, Lilian Greenwood, the title ‘Minister for the Future of Roads’. All this suggests that there may be changes from past policies in the offing, in a direction that could be consistent with the arguments I have been making.

Such new approaches inevitably raise questions about the competence of the Department for Transport that cannot just be attributed to misjudgements by past Conservative ministers. A point of comparison is Transport for London, which is generally agreed to be a world leading planner and provider of regional public transport and major roads. TfL has a good vision of how London’s transport system needs to develop, aiming to implement the Mayor’s Transport Strategy and consistent with his responsibilities for housing, the environment and for London’s economy. This vision involves major investments in rail, low-cost investments in active travel, plus operational improvements across the board. Such a vision requires validation of individual investments – the ‘vision and validate’ approach.

But here it is important to recognise that decision makers do not simply bring an open mind to consider a portfolio of potential investments from which they might choose. Generally, those in charge – senior and experienced people – will have a pretty good idea of what investments they would like to make, and can justify. They seek validation from analysts – modellers, planners, economists, engineers. Validation includes securing good value for money and complying with all legal requirements. It is thus not often that major misjudgements occur in the choice of projects pursued. The popularity of the new Elizabeth Line, formerly known as Crossrail, is a good example of what has been achieved, despite overruns of construction time and budget. Other successful projects have been the introduction of the Congestion Charge and the upgrade of erstwhile ‘Cinderella’ rail lines into the London Overground.

In contrast to TfL, the Department for Transport has had neither a vision nor a strategy, nor has been a ‘driving force’ in the proposal/selection and delivery of the potential ‘best’ schemes, or the promulgation of effective ‘system management’ concepts. What it has had are problems with the major sectoral ‘wish list’ expenditure programmes for road and rail, the economic benefits of which it has found difficult to convincingly justify, both at programme level and for individual projects, but creating huge pre-emptive budget requirements. It has overseen serious cost overruns on HS2, had many setbacks and criticisms in the courts in the face of litigation by those objecting to road schemes. And it has struggled to reconcile the impacts of a large road investment programme with the Net Zero climate change objective, having its overall decarbonisation plans for transport twice rejected in the courts.

My book discusses many of the proposed investments supported by the Department as case studies in the application of a defective appraisal methodology, including the virtually impossible to justify Stonehenge A303 tunnel, questionable smart motorway schemes (a programme cancelled by the previous government as the result of public anxieties about safety, but falling well short of expectations economically), HS2 (now truncated), and the extended saga of a third runway at Heathrow. In some cases, the analysis was forced to comply with a prior policy decision, in others key strategic economic benefits were poorly treated or disregarded.

There is now surely a good case for an independent review of transport investment appraisal and modelling to identify a fit for purpose methodology for an era in which the high-level strategic priority is decarbonisation. I hope my book might provide useful evidence and argument were such a review to take place.

My new book is available at https://uclpress.co.uk/book/travel-behaviour-reconsidered-in-an-era-of-decarbonisation/ free to download as a PDF.

This blog post was the basis of an article in Local Transport Today of 5 September 2024.

Professor Glenn Lyons has been developing the concept of Triple Access Planning over the past decade and has now published, with 17 co-authors, a 130-page Handbook setting out the approach in some detail. The essential idea is that nowadays we seek access to other people and places by three means: spatial proximity, physical mobility and digital connectivity, each employed to different degrees to meet our needs. Accordingly, if transport planners consider only the transport system, they are ‘dangerously blinkered’ and invite uncertainty into decision making by ignoring the other two systems, it is contended.

The focus on access (or accessibility) as the real objective, rather than movement, is very welcome as an approach to planning. Access is what we seek – to people and places, activities, services and employment, friends and family, for the opportunities and choice that improve the quality of our lives. Over the past two centuries, physical access using mechanised transport systems based on fossil fuel energy arrived with the Industrial Revolution and was rapidly developed, indeed was economically and socially transformational – though not without damage. Next came telecommunication, latterly offering apparently limitless digital connectivity, again having a revolutionary impact. Meanwhile changes in how land is used and the locations of activities relative to one another has reshaped the world out of all recognition.

There can be little dispute that the ‘three option’ thinking is very useful in putting transport provision itself in its proper place. Yet the Triple Access Planning approach, as set out in the new Handbook, has its limitations.

Triple Access Planning is stated to be a way of thinking that marks a change for transport planning from the ‘predict and provide’ paradigm to ‘decide and provide’. This is a fashionable shift of perspective, described as a ‘vision-led’ philosophy, for which there are good arguments in respect of addressing emergent issues such as sustainability. Yet the question avoided is whose vision, and who decides? The answer presumably is that of planners, and of the politicians they serve, both national and local, but who must nevertheless take account of the views of those whose taxes pay their salaries and who elect them into office. The democratic process often impedes the deployment of measures that planners would see as beneficial to the community, but which many members of the public may see as detrimental to their personal well-being, particularly if less car use is proposed. For instance, the Handbook cites as sound thinking the Scottish Government’s Climate Change Plan of 2020 that made a commitment to a 20% reduction in car kilometres travelled by 2030 compared to pre-pandemic levels –  an example of decide and provide, but one for which measures to implement such a substantial change have not been articulated. Generally, the Triple Access approach seems designed for planners and has comparatively little to say about the practicalities of gaining general public support for its proposals.

A second, and more substantial limitation of Triple Access Planning is the lack of economic content. Resources are always constrained, so that planners and politicians have to be concerned with the relative cost-effectiveness of different approaches to meeting access needs and their wider consequences.

There is quite a lot that can be said about cost-effectiveness of measures to enhance the three components of Triple Access Planning. Spatial proximity is very largely determined by the built environment we have inherited, whether the low densities of sprawling US cities such as Los Angeles, or the high densities of admired inner areas of European cities like Paris or Barcelona. Generally, UK cities are relatively low density, reflecting a preference for single family homes with gardens. While there is scope for what is called ‘gentle densification’ of existing communities, we could not afford, nor would we wish, to attempt large scale redevelopment of suburbs to higher density. The historic development of British cities therefore limits the opportunity to enhance spatial proximity.

On the other hand, enhanced spatial proximity is an option for some types of new build, for instance based on high rise apartments on urban brownfield sites. However, for new greenfield housing at low density, built to sell by developers, lack of spatial proximity seems not to be seen by purchasers as a disadvantage, although campaigners remonstrate at the lack of alternatives to the car. Occasionally, wholly new settlements might be created, as exemplified by Britain’s Post-War New Towns, the last of which, Milton Keynes, was designed to accommodate the growing car ownership of that era. Subsequently, Poundbury, an urban extension on the western outskirts of Dorchester masterminded by the Duchy of Cornwall (led by the then Prince of Wales), was designed as a walkable community, giving priority to people rather than to cars. Nevertheless, because Poundbury is small – 5,000 homes are planned – the mismatch between homes and jobs means that residents are likely to travel further afield for work, such that car ownership is higher than in Dorchester and the surrounding region, with 55% of residents using a car or van to get to work.

New built homes increase the national housing stock by only about one per cent a year, so it is the existing built environment, homes and facilities, within which almost all trip origins and destinations occur, that places a limit on improving spatial proximity, with little scope for cost-effective change.

Physical mobility meanwhile depends on the historic transport infrastructure already in place that accommodates all trips. There is much debate about adding capacity to the road and rail networks, and considerable public resources have been allocated for this purpose by successive governments. Yet adding capacity is costly, whether shifting earth, pouring concrete and rolling tarmac for new roads, or constructing track, tunnels, power supplies and signalling for new rail routes, so that the net addition to capacity is quite small. For the strategic road network, annual additional lane-miles barely keeps up with population growth. And for rail, the prospect of escalating construction costs may lead to truncation of plans, as with HS2, or to an unwillingness of decision makers to commit public money in the first place.

So the possibilities for cost-effectively increasing the physical capacity of transport infrastructure to enhance mobility are quite constrained. However, there is scope for making better use of existing networks by means of digital technologies, thereby increasing access, particularly on the railways where modern signalling and control technologies allow higher train frequencies to be achieved while maintaining safety standards. Digital technologies to increase effective road capacity are more difficult to implement, given the diversity of traffic, but warrant more attention than they are receiving, particularly to exploit the very general use by drivers of digital navigation, known as satnav in the road context. But in any event, higher speeds of travel are unlikely to be achievable by digital or other new mobility technologies, which limits increased access by physical mobility, given the constraints on the time available for travel within the 24-hour day.

Enhancing access by improved digital connectivity seems a more promising approach, given the scalability of the relevant rapidly advancing technologies and the resulting cost reduction, hence the ubiquity of digital connectivity, driven by Wi-Fi and Broadband that have facilitated a variety of telecom innovations and apps for online interaction, such as Zoom or Teams, and services such as Skype and FaceTime, as well as social media sharing and conversational networks, all at an affordable cost.

So enhanced access through the new digital technologies is a persuasive approach in theory, but what about the practice?

There has been a long-running but inconclusive debate about whether digital communications technologies can and will actually substitute for physical mobility, or instead mainly complement it, for instance by allowing people to cultivate wider social and business networks, with whom face to face contact from time to time would be important to sustain relationships, and the parallel desire to undertake ‘experiential’ activity through leisure travel. The forced cessation of travel during the coronavirus pandemic showed that we could make much more use of digital communications than we had previously. Although travel behaviour has not yet returned to pre-pandemic levels for all modes, it has come fairly close, and indeed sometimes exceeding prior levels, particularly car use and air travel. In respect of the journey to work, the tensions between desires of employees to work from home for part of the week, and the wish of their managers to have them in the workplace, seem not to have yet fully played out. But in any event, it would be hard to conclude that the desire for face-to-face access has changed substantially, let alone being in decline, despite the availability of cost-effective digital technologies that make remote personal interactions possible.

The pandemic also led to a boost to online retail, but subsequently growth returned to the prior trend. Much shopping is a social and hands-on activity, so a new balance will emerge between the physical and the virtual – perhaps in the quite near future. Yet public policy is focused on sustaining the vibrancy of town centres, not promoting digital connectivity as an alternative to bricks-and-mortar retail. More generally, digital technologies may be comparatively low cost compared to physical structures, yet cost-effectiveness requires the utility of digital technologies for access purposes to be assessed in comparison with physical mobility – with the outcome still to be determined. The comparative carbon footprint of electricity-driven digital activity compared with physical mobility, and its own shift to electric power, is similarly far from yet clear.

The Triple Access concept is welcome in that it encourages wide ranging thinking about the possibilities for meeting people’s needs for access. Yet when an assessment of the cost-effectiveness of measures that might be adopted is superimposed, the scope for implementing innovative measures becomes quite constrained.

A third limitation of the Triple Access approach is the lack of consideration of the basic characteristic of access, which is that it is subject to diminishing returns – the more access you have to any kind of service, the less the value of a further increment. The Competition Commission, as it then was, some years ago investigated competition between the main supermarket brands. This involved relating where people lived from census data to where the large supermarkets with car parking were located, finding that 80% of the urban population had three or more supermarkets within 15 minutes’ drive, and 60% had four or more – arguably offering good levels of choice. You could ask yourself whether you would need to drive further to have more choice in the weekly shop – if not, your demand for travel to supermarkets would be said to have ‘saturated’. This has come about over the years through growing household car ownership and investment by the supermarket chains in more large stores, both trends now largely played out.

For those who don’t run a car and rely on local food stores, similar developments have been widely seen, with the main chains opening small local branches and many thriving independent minimarkets staying open for conveniently long hours. In my own neighbourhood, for instance, in an inner London borough, there are branches of two chains and some four independents, all within ten minutes’ walk. However, there remain ‘food deserts’ in areas of low income where choice of outlets is limited.

How much shopping choice we need depends on the nature of the goods or services we seek. For standard products at fixed price, such as newspapers, the nearest shop suffices. For fashion goods, a trip to the city centre may be justified, plus a search of online outlets. Many services are routinely purchased online, insurance in all its forms, for instance, and much travel booking.

A second characteristic of access is that it increases, approximately, with the square of the speed of travel: what is accessible is proportional to the area of a circle whose radius is proportional to the speed of travel (recalling elementary geometry). A constraint is the density of the road network, highest in urban areas, lower in rural. But in any event, access increased markedly as car use replaced slower modes. It is the combination of access increasing with up to the square of the speed of travel while being subject to diminishing returns implies an expectation of the saturation of travel demand to achieve access to frequently used activities.

In practice, those who have available use of a car and/or good public transport provision, plus fast broadband, arguably have sufficient access to sources of most goods and services to meet their needs, implying that their demand for access has saturated. Demand saturation is a phenomenon that arises generally once uptake of some new innovation is widespread, washing machines for instance where the market now depends on replacement of worn-out models plus population growth. There is no reason to suppose that demand saturation would not apply to travel, although it is a topic neglected by investigators and theorists.

In conclusion, while Triple Access Planning encourages fresh thinking, the constraints on practical measures, and the circumstances in which these might be applied, seem thus far to have been underestimated. Limiting factors are insufficient consideration of public aversion to change, the cost-effectiveness of measures that might be adopted, and the fundamental characteristics of access benefits. Nevertheless, the aim of meeting the human need for access by means other than investment in transport infrastructure is a welcome extension to conventional transport planning and analysis that deserves further development.

This blog post is the basis for an article published in Local Transport Today 2 July 2024.

The recent publication of the Full Business Case (FBC) for the A428 Black Cat to Caxton Gibbet Improvements Scheme highlights the policy inconsistencies and misleading supporting analysis that typify road investments. We have the Introduction by the Roads Minister explaining that A428 has long been seen an important section of the strategic road network that required upgrade due to its problems of congestion, poor journey time reliability and resilience, and how accordingly the Scheme will enhance journey times, support local and regional economic growth, create jobs, and improve employment and the environment.

To justify these high level objectives, the 270 page FBC grinds through all possible aspects of the case for constructing ten miles of dual carriageway. This is impressive in its way, but is the effort ‘proportionate’, to use a favourite DfT term, I wonder? Perhaps the intent is to ensure the proposal is crash-proof in the event of any further legal challenge; or perhaps to deter potential challengers from initiating such challenge. Then again, the economics of the investment look pretty marginal, based on opaque reported analysis, so perhaps extensive quantity is seen as a counterbalance to thin quality in making the case for the Scheme.

Journey time savings for all classes of vehicles, of £633m, are claimed as the main benefit, as is usual (although in 2010 prices discounted to 2010, implying some antiquity to the modelling). But this is not split between business users (cars and road freight) and non-business (commuters and others), as must have been modelled, since each class has a different value of time. In other cases I have examined, the split between business and non-business has been shown, with time savings to non-business users almost entirely offset by increased vehicle operating costs, the result of local users diverting to take advantage of faster travel provided by the improved route. The economic case for a scheme depends on the scale of such diversion, since local users pre-empt capacity intended for longer distance business users. This failure to split the journey time savings looks like intentional obfuscation.

The time saving benefits are in any case offset by quite substantial carbon disbenefits worth -£182m. My impression is these are much more than in previous road schemes, reflecting updated carbon values promulgated by the former Department of Business, Energy and Industrial Strategy. So no longer are increased carbon emissions dismissed as de minimis, at least in economic terms. Nevertheless, if, as I expect, the long run benefits of the scheme mainly take the form of enhanced access, rather than time savings, the increased vehicle-miles-travelled (known as ‘induced traffic’), would increase externalities. So carbon disbenefits are likely to have been underestimated.

Whatever the magnitude, new road capacity must generate more carbon emissions. What needs to be spelled out is the total increase in carbon from the whole road investment programme, to see to what extent this impedes delivery of transport’s contribution to Net Zero. Regrettably, the new 114 page National Networks National Policy Statement, recently published, fails to prescribe programme level estimation of carbon emissions. If neither at programme level nor at scheme level, where is this significant and unwanted damaging impact to lie?

While the cost data in the FBC are redacted, presumably to protect National Highways position in other road scheme projects out to tender, the initial benefit-cost ratio (BCR) is estimated as 0.92. To make the investment at all viable, ‘wider impacts’ of £282m have been adduced to yield an adjusted BCR of 1.63. This scale of wider impacts seems very high for a non-urban scheme, based as it is on an elaborate, yet in reality, not much more than a back-of-the-envelope calculation. It may be that it is this tenuous boost to benefits, to put the Scheme in the DfT’s medium VfM category, that has necessitated the supporting assessment and sign off by the two accounting officers, the DfT permanent secretary and National Highway’s chief executive.

For my part, I suspect that optimism bias is at work to generate even an initial BCR of 0.92, requiring yet more optimism to get to 1.63. So I would not regard the figures in the FBC as robust, even though the analysis is presented as exceptionally extensive. Yet I have some sympathy for the highways engineers at National Highways, who see this scheme as necessary to create continuous dual carriageway between the M1 at Milton Keynes and the M11 at Cambridge, with onward travel to the ports of Felixstowe and Harwich. A stretch of single carriageway in what is otherwise a dual carriageway route is, to them, offensive. Naturally they seek to add capacity to reduce congestion and achieve a free-flowing network. This approach would also seem logical and persuasive to most local politicians and business leaders not versed in the principles of transport planning and the observed road user responses to additional capacity provision, let alone the minutiae of scheme appraisal and Benefit Cost Ratio calculation.

However, congestion on roads in well-populated parts of the country typically displays morning and evening peaks, indicating use by commuters, who have choices of route. Travel patterns are not fixed and are certainly influenced by network changes. So new free-flowing routes tend to attract additional traffic, whether by diversion in the short run to achieve the saving of journey time, or in the longer run through permitting longer trips within the travel time available. Both of these are beneficial but are not the benefits conventionally modelled, nor are they allocated to the categories of traffic that underpin the original justification for the scheme. Generally, where commuters and longer distance business users share road space, free flow is difficult to achieve, particularly at peak hours.

There is a gulf between the simplistic but erroneous headline justification for this and similar road investments, and the complex, opaque and misleading quantified supporting analysis. It would be good to find a common language to bridge this gap, based on a behaviourally realistic account of what is going on, what options there are to improve matters, and what is most likely to happen in practice if changes are made. Applying the concept of Heuristics is one possible solution.

Heuristics are simple rules – rules-of-thumb – for making decisions, coming to judgement, solving problems or shaping intuitions, that work well enough in most circumstances. I want to suggest that transport planners and practitioners would benefit from relatively simple heuristics in offering advice to decision makers about addressing perceived issues of system inadequacy and the justification for providing additional capacity in a range of circumstances.

This would mean distilling the evidence from research by academics and others to yield rules-of-thumb that are intuitively credible to both practitioners and decision-makers. One problem is that research findings are often based on case studies, specific to place and time, and are path-dependent, so generalisation may be difficult. Besides, the research literature in the area of transport studies has burgeoned in recent years, not necessarily to overall professional benefit, in part the consequence of the proliferation of open access journals that charge researchers for the cost of publication, rather than rely on library subscriptions; this creates an incentive for the journal to downplay rigorous peer review and editorial oversight in the interest of increasing income, and the consequence is a proliferation of case studies that may gain academic credit but are of limited general applicability.

Moreover, the research literature may overlook the authoritative information available in official publications, including statistical series, as well as in the unofficial ‘grey literature’ publications from think-tanks and others. Hence formal reviews of the ‘research literature’ may therefore be both unwieldy and incomplete, making it hard to see the wood for the trees and so difficult to draw useful conclusions. Government departments accordingly now seem often to commission ‘rapid evidence reviews’, which give consideration to a manageable number of selected papers to save time and effort, but selection may be biased, consciously or otherwise, to support the expectations of the commissioning department, and the most important recently revealed insight and understanding may not yet be included.

In these circumstances, I believe helpful Heuristics would need to be based on a deep and wide knowledge of both publications, practice and observed data, to establish a cogent and concise framework for analysis and decisions, in accessible language, not set in stone but subject to review in the light of new evidence and experience.

One area where rules-of-thumb may be particularly useful for transport planners and decision makers is in the tackling of road traffic congestion, central to the contemporary travel experience and to transport investment, such as the A428 Scheme, but for which repeated interventions have demonstrated little impact in practice. To the extent that relief may be achieved, this is more short term than long term. Yet huge amounts of public expenditure are justified by the objective of relieving congestion and boosting connectivity, with little evidence of success at outturn.

So, let me suggest some rules-of-thumb for thinking about road traffic congestion. I will not cite chapter and verse of the evidence in support, for which see my recent book.

  • Congestion arises in or near areas of high population density where car ownership is also high. More car trips might seek to be made at times of peak demand than the road network can accommodate. Delays ensue, which motivate some road users to make other choices, including adopting alternative routes or times of departures, alternative modes of travel where available, different destinations where there are choices (such as for shopping trips), or not to travel at all (such as ordering good online). Congestion therefore is generally self-regulating in that if demand increases, delays increase and more potential trips are suppressed. Daily gridlock or long tailbacks are uncommon and arise where there are unanticipated obstructions to movement.
  • Increasing road capacity has the effect reducing delays in the short term, but thereafter attracting previously diverted and suppressed trips, as well as permitting new and longer trips, consistent with the maxim that we can’t build our way out of congestion, known from experience to be generally true. The result is additional traffic, known as ‘induced traffic’, which in the short term is the consequences of diversion of commuters and other local users on to the new capacity to save time; and, in the longer term, of road users taking advantage of faster travel to make longer trips to increase access to desired destinations, as well as changing trip origins by moving homes.
  • Interventions that reduce vehicle use initially reduce delays, but this attracts back onto the network previously suppressed trips, thus restoring congestion to what it had been. Interventions conceived as intended to reduce vehicle road use include the promotion of active travel and public transport, congestion charging and road pricing, and consolidation of freight deliveries into fewer goods vehicles.
  • Reduction in urban carriageway available to general traffic can make more space available for bus lanes, cyclists and pedestrians. This initially can increase congestion delays, which leads to drivers making alternative choices. In the longer term the intensity of congestion is difficult to reduce, but the absolute amount of congested traffic would be lessened and could be better managed to benefit the whole population.
  • Induced traffic results in more vehicle operating costs and in additional externalities, including carbon and air pollutant emissions, which public policy is seeking to reduce.
  • The orthodox economic case for road investment relies mainly on the saving of travel time. Yet the evidence is that average travel time is a long term invariant, implying that people take the benefit of faster travel in the form of improved access – to people, places, employment, services and activities, with ensuing enhanced opportunities and choices.
  • Transport models that project travel times savings, comparing the with- and without investment cases, do not reflect the reality that improved access is actually the main beneficial outcome. Access is subject to diminishing returns, implying declining returns to road investment as the road network matures.
  • The car is very popular for its utility in door-to-door travel over short to medium distances, as well as over longer distances when alternatives are less attractive, provided  congestion delays are acceptable and parking is available at both ends of the journey. These conditions may not apply in city centres, where public transport, particularly rail-based in all its forms, provides a speedy and reliable alternative to cars and buses on congested roads. But beyond city centres, in suburbs, towns and rural areas, the popularity of the car as a mode of travel against available alternatives is difficult to challenge.
  • Promotion of active travel has limited impact on car use. The evidence is that improved cycling facilities mainly attracts people from buses, which reduces farebox income and leads to reduced service levels or a requirement for more subsidy. It is difficult to be pro-active to successfully increase walking, which is the slowest mode of travel, permitting the least access to desired destinations for most people.
  • The built environment, within which are located nearly all the homes, facilities and services that are trip origins and destinations, is largely a given, with limited opportunity to increase density through brownfield or infill development. Creation of new communities on greenfield sites with choice of travel modes has proved difficult. Accordingly, there is limited scope for the creation ’15-minute cities’, an aspiration of many urban planners, aimed at reducing car use, congestion, pollution and carbon emissions.
  • As well as being popular for getting from A to B, for many people ownership of a car is attractive for a variety of lifestyle reasons. The fact that cars are generally parked for 95% of the time is a seemingly persuasive economic argument for car sharing in its various forms. But conversely, the desire to own a resource that is so little used is an indication of the value attached to ownership and convenience. This is in part why it proves difficult to shift car owners to other modes. Cars parked at the kerbside reduce carriageway available for vehicles on the move, contributing to congestion delays and deterring some road users.
  • The wide use of digital navigation (known in the roads context as satnav) has the effect of redistributing traffic. Commuters and other local users divert from existing routes to new capacity on major roads, to save time, pre-empting capacity intended for longer distance business users, including freight, so detracting from the projected economic benefits of the new capacity. In addition, traffic diverts from congested major roads to minor roads that offer a less congested alternative route, such minor roads previously used only by those with local knowledge, making them ‘rat runs’ less suited for active travel and detracting from quiet residential environments.
  • The most advanced forms of digital navigation predict journey times, so reducing uncertainty about time of arrival, which is what bothers road users most about the impact of congestion. Digital navigation is thus arguably the best means available for mitigating the perceived impact of road traffic congestion, as well as being vastly cheaper than providing new road capacity.

These rules-of-thumb about observed realities are proposed as ‘good enough’ ways of recognising and addressing the problem of congestion that we face on road networks and identifying effect means of mitigation. I suggest three questions to structure shared thinking about this and the other problems we face, amongst transport planners, politicians, other decision makes and influencers:

Q1 What’s going on here?

Q2 What options do we have to do better, that are both cost-effective and affordable?

Q3 What choices to make?

Responding to the first two questions is the task of analysts, including transport planners, economists and policy advisers, approaching problems with an open mind. Responding to the third question, with the benefits of the answers to the first two, is the task of decision makers in the public and private sectors, as well as advocates of all kinds. Better decisions would be made if those involved are clear about their roles, tasks and expectations. Heuristics, of the kind outlined above, could help them acquire good intuitions of the cost-effective options available, and give others greater insight into the basis on which decisions are made.

Nevertheless, some may argue that such heuristics serve to over-simplify what is bound to be a complex analysis of what’s going on. Albert Einstein said: ‘Make things as simple as possible, but no simpler’. Are these heuristics for understanding and reacting to congestion good enough or are they too simple? Do we still need the full panoply of the Department for Transport’s Transport Analysis Guidance to present to a small coterie of people a theoretical analysis based on problematic behavioural assumptions as to what should be done? Or, as some may believe, to justify, through virtually impossible to decipher analytical complexity (as represented by the likes of A428 business case), someone’s original hunch, then bought into tenaciously by the scheme’s promoting bodies. My own view is that narrative and dialogue based on heuristics would offer an alternative approach, well worth trying, to answer the three questions above in a generally understandable way.

This blog was the basis of an article in Local Transport Today of 21 March 2024.

Behaviour change is a topic of continuing interest to transport professionals, with current focus on getting people out of their cars, to use instead public transport, walking or cycling. The main policy motivations are to reduce the harmful consequences of car use, in particular tailpipe carbon emissions and air pollutants, as well as to reduce road traffic congestion, enhance the sense of urban place, increase healthy exercise and improve the economic viability of public transport. This was the topic of contributions to a recent Transport Thinking Forum Round Table discussion on achieving behavioural change, organised in association with the TAPAS network. Here I offer some further reflections on the interesting contributions and on the practical possibilities.

A common approach to effecting behaviour change is conceptualised by the simple idea of ‘sticks and carrots’ – punishments for undesirable behaviour and rewards for better behaviour, judged against policy objectives. However, this was criticised as an unhelpful metaphor by Pete Dyson, a behavioural scientist who has worked at the Department for Transport, now at the University of Bath. He regards the concept as too simplistic and also problematic because the ‘stick’ element prompts pushback from those who see themselves as adversely affected, as well as from the politicians who aim to represent them, car users in particular (see also the book he co-authored with Rory Sutherland: Transport for Humans – Are we nearly there yet?).

As alternatives to sticks and carrots, there are other concepts available including: Avoid-Shift-Improve, a general approach to environmental sustainability; the Upstream-Downstream model of behavioural change developed by the Behavioural Insights Team; and the COM-B model developed at UCL, which posits that behavioural change can only come about if there are in place all three elements of Capability, Opportunity and Motivation. The COM-B approach has been widely used in the public health context, for instance to encourage smoking cessation, and is one of a number of techniques that have been applied with success to improving road safety. The Scottish Government has stated that it has considered interventions to reduce car use in the context of the COM‐B model, although no detail has been provided.

Reducing smoking and improving road safety are generally seen as desirable objectives, so behavioural change interventions go with the grain of public opinion. But the objectives of reducing car ownership and use are very different, given that three-quarters of households in Britain own cars, which are seen both as useful for their utility in getting from A to B, as well as engendering good feelings associated with ownership (see my paper about Car Dependence). The M of COM-B is therefore largely lacking, so attempting to reduce car use by measures based on behavioural insights alone would be pushing uphill. On the other hand, interventions to foster electric vehicle purchase could be effective since the Capability to drive is as for internal combustion engine vehicles, there is Opportunity to purchase EVs, albeit only a limited used car market at present, and Motivation takes the form of lower operating costs and environmental virtue.

Measure to promote EV uptake, such as investment in public charging  points, can be seen as examples of the well-known approach known as ‘nudging’, a concept from behavioural economics that proposes adaptive designs of the decision environment as ways to influence the behaviour and decision-making of groups or individuals. Nudging is not a stick, in that compliance with the intention of the nudge is optional, nor is it straightforwardly a carrot in that the benefits of compliance may not always be self-evident. Richard Thaler, Nobel laureate in economics and a populariser of the concept, has cited satnav technology as an example: you decide where you want to go, the app offers possible routes, and you are free to decline the advice if you decide to take a detour. While this is a neat example, its ambition is quite limited. Nudging people to make significantly less use of cars by means of such ‘soft’ measures would seem likely to have only small impact, in the absence of complementary ‘hard’ unavoidable interventions.

One challenge to the usual view of behaviour change in the transport sector was put by Tom Cohen of the University of Westminster, at the TAPAS meeting, who argued that the overwhelming majority of interventions can be expected to lead to changes in behaviour, so that ‘behaviour change’ is simply the right way of doing transport planning, and not a subset of interventions such as those based on marketing or by appealing to our better nature. In short: transport is movement; movement is behaviour; so transport planning is travel behaviour planning. The implication is that we should look to packages of complementary interventions, of the kind envisaged by transport planners, to achieve behaviour change.

Also at the TAPAS meeting, Lisa Martin, of consultancy Steer, reviewed UK experience of packages of interventions aimed at changing travel behaviour, including those supported by the Sustainable Travel Towns demonstration projects and the Local Sustainable Travel Fund. Evaluation indicated that while high value for money could be obtained, as judged by the benefit-cost ratio, yet the impact on car use and/or traffic levels was quite small, of the order of 2%. This has not been sufficient to ensure that such packages are in the mainstream of approaches to transport decarbonisation, where typical aspirations of local and regional authorities are to achieve 20% reductions in car use by as early as 2030. Moreover, the ‘cost’ represented in the benefit-cost ratio is the economic cost. What is disregarded is the political cost that may be experienced by politicians, local and national, in advocating measures that engender pushback from those who feel they would be adversely affected, drivers and others.

There is certainly merit taking a broad view to identify packages of measures that might persuade, enforce or nudge travel behaviour change in directions helpful to wider policy purposes. Yet in practice much of the debate in the transport sector is about the consequences of investment in new road and rail capacity, the behavioural consequences of which tend to be multifaceted, yet which is supported by analysis and modelling that narrowly focuses on estimates of economic benefits that make simplifying assumptions about changes in travel behaviour. There are opportunities for behavioural scientists to question these simplifying assumptions, in particular that the main benefit of investment that results in faster travel is the saving of travel time that is used for more work or leisure activities. On the contrary, there is much evidence that, over timescales relevant for investment appraisal, the main benefits take the form of enhanced access – to people and places, family and friends, employment, services and activities, with ensuing increases in opportunities and choices. The travel-time-saving simplification is computationally convenient but does not capture the real behaviour of users. This means that conventional transport models whose outputs are traffic speeds and volumes, comparing with- and with-out investment cases, are behaviourally misleading. Models that project changes in access would be a better basis for investment decisions, as behavioural analysis would reveal.

Nevertheless, given that the conventional methodology for investment appraisal is so well established, a consequence is a search for approaches to effecting behavioural changes that can be pursued outside this orthodoxy, hence the continued popularity of ‘sticks and carrots’ as well as interest in alternative approaches that avoid direct confrontation with the economists.

The general problem we face is that the system of travel/transport is particularly complex, has evolved over time in parallel with our built environment, and where remedies to problems tend to be specific to particular locations. This makes it difficult to gain a sufficiently deep understanding of what is going on and what options are likely to succeed in ameliorating detrimental aspects and/or enhancing positive features. Einstein said: ‘Everything should be made as simple as possible, but not simpler’. While perhaps more straightforwardly relevant for physical systems, this maxim begs the question of how simple descriptions of complex systems can be before the charge of oversimplification could be legitimately laid. My own view is that there is scope for simplification through the application of heuristics – rules of thumb, mental shortcuts – that are good enough accounts of what’s going on and what our options are, and that will promote common understanding – a topic on which I will write at greater length on a future occasion.

In the end, the test is ‘what works’ – the observed outcome in the real world of behavioural interventions. Reasonably clear outcomes may be observable in the case of sticks, such as adjustments to taxation, implementation of changes in road layouts or of charging schemes aimed at reducing vehicle emissions or traffic congestion. Similarly, the impact of carrots in the form of cash incentives can often be measured. But more nuanced interventions such as nudges may be harder to document.

Outcomes of behavioural interventions may be observed from experience in other countries. Yet local conditions and behavioural responses may be significantly different from those in the UK. For instance, Paris was one of the first cities to allow rental electric scooters, but then was one of the first to ban them on grounds of safety, following a referendum. But that is not to say that other cities would follow the example of Paris. Nevertheless, the idea of trialling an intervention for a defined period and then having a vote may be a practical way of testing public acceptability. Stockholm’s congestion charge was trialled for a seven-month period, then turned off prior to a referendum, the outcome of which led to permanent implementation.

The substantial scope for travel behaviour change was illustrated by the coronavirus pandemic, which had a major impact on travel behaviour largely through unavoidable constraints imposed by governments, an example of a big stick, deployable in extraordinary times. But once these constrains were removed, people reverted largely to their previous travel behaviour, which reflected prior choices about where they lived in relation to where they worked, to where family and friends lived, where their children were educated, as well as activities and services they had become accustomed to access. Such reversion implies that large changes in travel behaviour could not realistically be delivered in a democratic society in normal times.

While there is undoubted scope for the application of behavioural science to investigate how travel behaviour might usefully be changed incrementally, in practice on/off trials plus referenda might provide both a practical test of acceptability as well as a justification for initiatives by sufficiently bold politicians. And after a decision to implement permanently, evaluation on short-, medium- and longer-term timescales would help inform subsequent decisions.

Yet when contemplating the possibilities for travel behaviour change, we should not fail to recognise that the car has provided valued access benefits to a majority of households, notwithstanding its problems. Persuading people to use their cars less would therefore require provision of alternative modes that feel to them at least as good, reinforced by effective, probably incremental constraints on car use. Whether we use the shorthand of ‘carrots and sticks’ to describe such complementary measures is less important than finding the funding to invest in attractive alternatives to the car, particularly rail-based travel in urban areas where the economic viability of public transport is most feasible. In the absence of good alternatives, getting people out of their cars would be difficult, regardless of the sophistication of our behavioural analysis.

 
 






					

The coronavirus pandemic caused major dislocation in society, not least to the amount and modes of travel, with many similarities across countries, albeit differing in detail depending on local constraints imposed on work and travel. This amounted to a ‘natural experiment’ in that an exogenous event led to large changes in travel behaviour over a two-year period, 2020-2021, before the cause faded away and normal life largely resumed, yet with some possible permanent long-term consequences. The findings of the National Travel Survey for 2022 are ambiguous as to whether we are on the path to pre-pandemic normality, or whether some permanent changes have arisen. Transport for London has recently published its annual Travel in London report for 2023 that includes relevant data for the capital. So it is worth considering the evidence for pointers to the future.

The pandemic led to two main changes in how we live and in the related demand for travel: more working from home and more shopping online.

Working from home

While some of those who do not need face-to-face contact with customers, clients or colleagues have always worked from home, the pandemic resulted in a step-change in the numbers adopting this practice. In some cases, this was a sub-optimal response to an emergency, for instance in the education sector. In other cases, this reflected advantages of not travelling to a workplace for at least part of the week, avoiding both the time and discomfort of commuting, flexibility of when to work, and perhaps benefiting from the avoidance of interruptions in the privacy of the home environment.  

For some organisations, it has been found that the workplace office could be dispensed with entirely. For many others, some form of hybrid working has emerged, with employees spending part of the week in the office, although the long-term stability of this outcome is yet to be seen. The extent of hybrid working reflects a balance between the preference of many employees for working at home and the preference of many of their managers for having people in the office – for oversight, to stimulate creative interactions and to induct new staff into the culture and practices of the organisation. This balance is affected by the state of the employment market – the demand and supply of employees with appropriate skills. The market was tight following the pandemic, with low levels of unemployment as many older workers decided not to return. But over time, this balance could shift, particularly if the benefits of agglomeration are as significant as had previously been supposed, so that businesses that have more staff on site prove to be more successful and profitable. On the other hand, businesses that commit to hybrid working may be able to attract staff from a wider area, as well as reducing the expense of maintaining office space for the full complement of staff.

Surveys by the Office for National Statistics of working adults in Britain found that while 50% reported working from home at some point in the previous seven days in the first half of 2020, early in the pandemic, this had fallen to 40% in early 2023; throughout 2022, when the restrictions of the pandemic had been lifted, the percentage of working adults reporting having worked from home varied between 25% and 40%, without a clear upward or downward trend, indicating that homeworking was resilient to the end of travel restrictions. Professionals and those in higher income bands were more likely to work from home, whereas those who require face to face contact with clients or personal engagement with facilities resumed travelling to their workplace – in education, healthcare, hospitality, retail, manufacturing and laboratories.

The emergence of a new normal involving both fully remote and hybrid working raises a question about the value of agglomeration benefits from learning, sharing, and matching in city centres. Estimation of the economic value of agglomeration has been based on econometric analysis addressing the change in productivity in relation to the change in effective economic density, with the biggest benefits accruing to knowledge-focussed businesses, despite remote or hybrid working being most feasible for such businesses. The observed movement of businesses to central locations in recent decades reflects net agglomeration benefits, the positive benefits being offset by the negative, the balance being affected by technological developments. But this may be changing.

Fleet Street, for instance, was once the physical location of the national newspapers in central London, with printing presses in the basements, print workers on floors above and editorial staff on the upper floors. This was a classic cluster, with benefits from shared facilities and staff, allowing news to travel faster and gossip to flourish. But there were offsetting disbenefits: newsprint had to be brought into central London, from where newspapers were distributed across the country overnight, and there were restrictive labour practices reflecting trade union power when the product had to be made anew each day. But then the advent of digital typesetting allowed newspapers to be printed at remote printworks with better access to transport networks, so that the editorial offices could disperse to scattered locations around London. Nowadays, ‘Fleet Steet’ is a metaphor for the newspaper industry, no longer the actual location. With hindsight, the agglomeration benefits and disbenefits were more finely balanced than had been supposed, so that new technology could tilt the balance in favour of dispersion of the cluster.

A question, then, is whether something similar may be happening more generally to knowledge-based businesses that had been benefiting from clustering in city centres. It has long been suggested that modern information and telecommunications would lead to the ‘death of distance’, yet the benefits of agglomeration seemed to trump those associated with dispersal. But then the shock of the pandemic both enforced working from home where possible and brought forward technologies to facilitate online meetings and collaboration based on broadband telecommunications that had steadily been improving. The disbenefits of agglomeration to employees in the form of the time, cost and discomfort of commuting became immediately apparent, with a consequential reluctance to return full time to the workplace. The balance of benefits and disbenefits may have shifted in favour of dispersal, although it may take time to reach a settled outcome.

For employers, increased working from home could lead to a decrease in demand for office space in the centres of cities, although this would depend on how workspace is managed to accommodate staff who are there for only part of the week. Shrinkage of space to save rental costs could make the office a less attractive destination. High quality premises with good facilities within and nearby would be preferred, to attract high quality staff. Older, lower quality buildings are becoming redundant, particularly on account of regulatory requirements to improve the energy efficiency of rented buildings. This presents opportunities to repurpose such redundant workplaces, as has long been the case by creating loft apartments from historic warehouses. The scope for repurposing more recent office accommodation can be limited by the depth of floor plan, since windows would be expected by residents of flats, and by the core location of services. Creation of laboratory space, hotels and student accommodation are being considered. Perhaps the simplest repurposing would be a reversion to residential use of inner city eighteenth and nineteenth century houses built for families with servants but subsequently converted to offices. Such repurposing would fit the concept of the 15-minute city or 20-minute neighbourhood where most needs can be met by active travel within a short distance. However, with many tenants and landlords bound by long term leases, it will take time for the extent of the full changes to occupancy to emerge

While reduced use of public transport for commuting means less crowding at peak times, it also results in less revenue for the operators and so either more subsidy is required, or the outcome is poorer service and/or higher fares. This raise the question of the role of bus and rail travel in sustaining the economic and social vibrancy of towns and cities, particularly those whose density is such the general use of the car is not viable. The scope for raising fares is limited by use made by those who cannot afford a car, which means that some external source of funding support is required. Support from government was increased substantially during the pandemic as an emergency measure, but the longer-term position remains to be seen. Transport for London (TfL) has been more dependent on operating income from passenger revenue than other major cities, hence it was hit harder by the loss of fare income during the pandemic so that tortuous negotiations with central government were required to avoid serious loss of services. The case for increased external subsidy to sustain high quality public transport fits well with the need to decarbonise the transport sector by offering alternatives to car use, given that internal combustion engine vehicles will be dominant for some years to come.

It is possible that the time saved by commuting less will be used for other travel, given the long run invariant hour a day of average travel time. If this other travel is local active travel, cycling or walking, that would be helpful for reducing the environmental impact; if by car, less so, particularly if commuting had been by public transport. Working from home also allows living more remotely from the workplace if travel to work is less frequent; this leads to changes in residential property prices as between urban and rural locations, and new construction where land with planning consent is available for development, with consequential changes for travel behaviour, particularly increased car use.

Online shopping

The other shift prompted by the pandemic was to online retail, growth of which was accentuated markedly. Yet shopping is also a social activity, and the suitability of many goods are best judged first hand, whether the feel and look of fashion items or the bulk of furnishings. Data for internet sales as a proportion of total retail sales had been on a steadily increasing trend before the pandemic, rising from around 3% in 2007 to 19% immediately before the pandemic. It spiked to reach 38% in early 2021 before falling back to 25% in mid-2022, broadly returning to trend, although for how long the upward trend will continue is as yet unclear.

The main impact of this shift to online shopping has been to reduce the attractiveness of city centre department stores, some chains of which have closed entirely while others have shut some branches and repurposed floor space in continuing locations. Stronger city centres that relied on a wide catchment area were most affected by the pandemic, while highstreets in economically weaker cities and towns were less affected, although many were already experiencing difficulty in attracting shoppers and shops on account both of general economic conditions in towns that had lost major industries and the shift to online retail. Over time, rents will adjust to a lower demand for retail floor space, either allowing new entrants or repurposing for other uses.

Implications for travel demand

Department for Transport monitoring data showed that, by April 2022, motor vehicle use nationally had returned to just over 100% of pre-pandemic levels. Public transport use grew back at slower rates and some components have tended to remain below pre-pandemic levels: by late 2023, national rail use was 85% of that observed in the same period in 2019, London Underground use a little higher, and bus use was about 90%, although there have been significant fluctuations due to school holidays, weather events, tourist flows and industrial action. Use of the Underground to central destinations bounced back more quickly at weekends than in the week.

There was a burst of recreational cycling during the first lockdown, reaching a peak of 63% above a 2013 baseline in mid-2021, falling back to a 24% increase above 2013 in late 2022, consistent with a modest rate of long-term growth. Although there were many adaptations to urban roads at the outset of the pandemic to facilitate cycling as an alternative to crowded public transport, the ultimate impact of this will not be clear until the extent of return to the office becomes evident.

The findings for 2022 as a whole, from the National Travel Survey, show only partial return to pre-pandemic levels, which may reflect the emergence of the Omicron variant in late 2021, even though travel restrictions were lifted by February 2022. Thus, average travel time prior to the pandemic was close to 60 minutes a day; during 2020 and 2021 it fell to about 45 minutes, but rose in 2022 to 53 minutes. It would not be surprising if average travel time returned to an hour a day in 2023, although it remains too early to rule out some longer term change in travel behaviour, for instance from increased working from home. Thus, the average number of commuting trips in 2022 was 85% of that in 2019, whereas the average number of education trips (including escorting) was 94% of the earlier year, indicating the greater opportunity for working from home in contrast to studying at home. Average car mileage in 2022 was 89% of that in 2019.

Data published by Transport for London provide a more granular account of the position as of late 2023 (see Figure). Overall public transport demand reached 90% of the pre-pandemic baseline. There has been a consolidation of weekday travel on Tuesdays to Thursdays, where demand is typically higher than on Mondays and Fridays (particularly on rail modes), although only 26 per cent of all London residents have the option to work from home, reflecting a ‘blue collar’ versus ‘white collar’ difference. There is also more travel on weekends than on some weekdays, and slightly longer average journey lengths, all of which appear to be becoming established features of post-pandemic demand.

Conclusions

A key question is whether the travel changes triggered by the pandemic will have long term impacts that will help achieve transport decarbonisation. The evidence is that car use rebounded towards pre-pandemic levels faster than public transport use, where full recovery has yet to occur, and may not do so if working from home persists as an alternative to the full week in the workplace. Active travel at best shows a slow growth trend.

The pandemic has shown that we could make major changes to lifestyle and travel behaviour under the impetus of concerns about personal health. Coming out of the pandemic, some analysts saw indications of a long-term shift to travelling less, notably those working from home making less use of the car. It is possible that working from home will prove to be a long term feature for those for whom it is practicable and where employers are amenable, resulting in more agreeable and less crowded and congested commuting. Yet this leaves open whether and how the saving in commuting time might be used, whether for nontravel activities or for other kinds of journey purpose, and by what mode.

The full impact of the pandemic on travel behaviour therefore remains to be seen, yet the emerging evidence suggests that we largely reverted to pre-pandemic travel behaviour, particularly by car, once the threat to health had receded. The impetus of the climate emergency is less immediately pressing, and so we persist in travel behaviour that meets our needs for access to people, places, activities and services, with the opportunities that ensue, hoping that advances in technology would avoid having to make hard choices about travelling less. Those seeking substantial reductions in car use to mitigate climate change can take but little comfort from the pandemic experience.

This blog was the basis for an article in Local Transport Today 23 January 2024.

The National Infrastructure Commission published its Second National Infrastructure Assessment on 18 October. The Commission’s objectives, set by the Government when it was established in 2015, are to support sustainable economic growth across all regions of the UK, improve competitiveness, improve quality of life, support climate resilience and transition to net zero carbon emissions by 2050, all within a specified long-term funding envelope for its recommendations.

The NIC’s remit is to issue a comprehensive analysis of the UK’s infrastructure requirements once every five years. This covers all economic infrastructure sectors, setting out recommendations for transport, energy, water and wastewater, flood resilience, digital connectivity and solid waste. The Assessment takes a 30-year view of the infrastructure needs within UK government competence and identifies the policies and funding to meet them.

First, I will look at some of the key conclusions and recommendations concerning transport from the NIC’s analysis, which should be fairly uncontentious, at least for transport planners and practitioners:

  • The public transport networks of England’s largest cities under-perform relative to comparable European cities. Initial priorities for investment should be in Birmingham, Bristol, Leeds and Manchester and their wider city regions, to prevent growth being constrained. The scale of capacity increases required justifies investment in rail- or tram-based projects. The government should make financial support conditional on cities committing to introduce demand management measures to reduce car journeys in city centres, and cities should provide a contribution of at least 15-25% to the funding of large projects, whether from fiscal devolution or transport user charging.
  • Transport budgets should be devolved to all local authorities responsible for strategic transport so that all places are able to maintain existing infrastructure – for example improving the condition of road surfaces – and invest for local growth. This will also help places develop locally led infrastructure strategies through which transport investment can be considered against long term goals and planned alongside housing and land use development.
  • For the national road and rail networks, the government’s first priority should be to maintain existing networks by investing adequately in maintenance and renewal, including ensuring resilience to climate change impacts.
  • In order to align the processes of road and rail capital investment, the government should set a long-term investment pipeline across road and rail around an indicative total budget envelope and with clear common strategic objectives. This should incorporate a strategic vision for the main transport corridors that includes both road and rail, ensuring that they are considered together and not separately.

The NIC goes on to say that the cancellation of HS2 beyond Birmingham, which happened only at the beginning of October, after the Assessment had been completed, leaves a major gap in the UK’s rail strategy around which a number of cities have based their economic growth plans. A new comprehensive, long term and fully costed plan is needed, says the Commission, to set out how rail improvements will address the capacity and connectivity challenges facing city regions in the North and Midlands. Who could argue with that?

More problematic, in my view, is the NIC ‘s proposition that the government should plan and invest in enhancements to the road network, targeting under-performing sections that can facilitate trade in goods, and provide better connections between cities to facilitate trade in services, observing that it is not clear that this happens at present. Accordingly, the NIC has developed a portfolio of road enhancement options, based on a connectivity metric developed by consultants, that gives each place in Britain a score to denote how well connected it is to other places, calculated by taking the average travel time between a given place and other places in Britain, and weighting them by population and distance, which are useful indicators of likely demand for travel between places. This approach is used to identify the worst performing routes on the network with substantial demand potential between key cities and towns (see map in illustration). The portfolio has been developed within a proposed budget for road investment to cover the next 20 to 30 years.

In support of its proposals for road investments, the Commission states that better connectivity will help improve trade efficiency, making it easier for businesses to move freight and trade goods and services. However, the evidence for this is problematical. For instance, one source cited by the NIC concludes that for an inter-regional transport investment, economic activity may shift either to the lower productivity region (the periphery) or to the higher productivity region (the core), the outcome depending on the underlying economic conditions and the type and scope of the investment. This is known as the Two-way Road Effect.

The emphasis of the NIC ‘s analysis is on trade in goods and services, only indirectly on non-business travel. Yet adding capacity to road and rail routes accommodates and generates more use of all kinds. On motorways, for instance, there is evidence that the increased capacity arising from converting the hard shoulder to a running lane results in local users, commuters and others, diverting to take advantage of a faster journey, pre-empting capacity intended for longer distance business users. A low connectivity metric score may well arise from delays due to morning and evening traffic congestion, indicating the existence of substantial car-based commuting. This suggests that enhancement of capacity could be expected to further increase in use by commuters, with little benefit to trade in goods and services. So, I would contend, the NIC’s approach to connectivity is too simplistic.

A further problem with the NIC’s analysis is that although it recognises that road investment will need to be compatible with plans to decarbonise transport, it concludes that the additional emissions from its proposals will not themselves substantially alter the scale of the challenge (which must therefore be borne by the plan to achieve widespread vehicle electrification by 2035). This conclusion is based on embracing the Department for Transport’s projections of road traffic demand growth of 10-28% by 2035 (as indicated in the DfT Decarbonisation Plan), while a road enhancement programme over that period would be expected to increase demand by only around 0.6 to 1.3% (based on historic evidence from a number of studies).

However, the rule of thumb, based on general experience, is that we cannot build our way out of congestion, so any increase in capacity will result in more journeys (good for trade), it will also mean more traffic, resulting in more carbon emissions – at least until fossil fuels are eliminated from road transport – and restoring congestion to what it had been (not good for trade). The Commission’s analysis, suggesting that the additional carbon emissions from its road investment proposals are relatively small, is unconvincing. What is missing is an estimate of the total additional carbon emissions from its programme of road investment, to be compared with the DfT Decarbonisation Plan projection of 620-850 MtCO2 savings from vehicle electrification between 2020 and 2050. If the total additional carbon emissions from the proposed road investments turns out to be relatively small, this implies relatively little benefits to trade; if they are large relative to the impact of vehicle electrification, then the pathway to net zero is put at risk.

A lacuna in the Commission’s analysis of transport infrastructure investment more generally is the failure to consider the application of digital technologies, both to the highway network and the vehicles using it, to enhance the performance of the system overall. The exemplar for this is the application of digital signalling on the railways that allows shorter headways between trains at peak times, thus increasing the capacity of existing track.

Conclusion

I had high hopes for the NIC as an alternative source of policy advice and appraisal methodology when it was set up in 2015. Its analysis of rail investments for the Midlands and North of England offered fresh thinking and was influential in shaping the Government’s plans published in 2021. But the Commission’s proposals for road investment are disappointing, both as regards methodology and conclusions. I suspect at least part of the problem is that its efforts are spread across the whole range of infrastructure investment it is required to cover, so that there is too little capability for deep thinking about how the road network functions and how additional capacity impacts on performance. The NIC needs to develop better models, methodologies and data sources if it to offer fresh thinking for road investment and challenge conventional wisdom and assumptions. If not to provide fresh thinking to that hitherto applied by the DfT, what is the purpose and benefit of the Commission?

Moreover, the Commission was badly unsighted by the Prime Minister’s announcement of the truncation of HS2. The failure of the Government to engage with it on such a major decision prompts a question about the purpose and status of the Commission. The politically-driven redistribution of the funds allocated to HS2 to local transport schemes is quite contradictory to the long term analytically-driven approach that is the remit of the NIC. So, while in principle, analysis of long term requirements for infrastructure investment must be right, in practice short term budgetary constraints and political priorities can render the long view nugatory. One has to ask whether there is a future for the NIC.

A Labour government might well be more sympathetic to the NIC’s role, given that the party in opposition in 2012 established a review of infrastructure planning under Sir John Armitt, now chair of the NIC. That review indeed proposed a National Infrastructure Commission be established. Labour has plans for major capital investment to support the transition to net zero, so having a source of independent advice on such expenditure may be continue to be attractive.

Indeed, there may be a case for merging the NIC with the Climate Change Committee, given the overlap of functions and their cross-departmental approach to future demand and supply. Yet as long as individual departments and their ministers retain responsibility for their budgets and spending plans, with the associated tendency to take a short term view, the strategic may continue to be subordinate to the politically pragmatic.

This blog post was the basis for an article in Local Transport Today of 28 November 2023

The planning system for adding significant capacity to national rail and rail networks includes a national policy statement that obviates the need for discussion of national policy at local planning enquiries. The existing statement dates from 2015, and the Department for Transport has been consulting on a updated version that takes account, in particular, of the development of policy on transport decarbonisation. The House of Commons Transport Committee has published a critical report that highlights shortcoming in the DfT draft. I submitted evidence.

The DfT draft fails to reconcile the wish to continue investment in additional road capacity with the need to achieve Net Zero objectives. We await with interest the final text of the policy statement, to see if the Department can do better, so lessening the risk successful challenges in the courts.