Travel

The new Labour government includes a junior minister in the Department for Transport with responsibility for roads, but with the unusual title of ‘Minister for the Future of Roads’, perhaps implying that the future will not be business as usual –  likely to be the case, in my view. Consistent with this, the Department has established a panel of external experts to provide advice on strategic considerations for its capital investment portfolio. The government is also establishing a new body, the National Infrastructure and Service Transformation Authority (NISTA), combining the functions of the National Infrastructure Commission and the Infrastructure and Project Authority. NISTA will be located in the Treasury and is intended to bring oversight of strategy and delivery under one roof, supporting the development and implementation of a ten-year infrastructure strategy.

Several sets of eyes are therefore going to be looking hard at where investment is genuinely needed to support the Government’s key missions, a dominant one of which is delivering economic growth.

There is a general belief, voiced by the Prime Minister, other politicians and many industrialists, that we need to invest more in infrastructure to facilitate economic growth, decarbonisation and other policy objectives. To be sure, the case is persuasive for investment in new electricity sources of supply and transmission, in the water industry to clean up effluents and build new reservoirs, in fast broadband, in flood defences and in solid waste disposal. But transport is different, and the perceived links between infrastructure provision and economic development not as hard-wired as has previously been thought, as I argue in my new book, Travel Behaviour Reconsidered in an Era of Decarbonisation.

Personal travel in Britain, on a per capita basis, has not increased over the past 25 years. According to the National Travel Survey, on average we are on the move for about an hour a day, making about a thousand journeys a year, covering some 6500 miles by all travel modes (except international travel by air, a different story). This is unlikely to increase in the future. We have reached the limits to the speed of travel with existing technologies, and new technologies, such as electric vehicles or automated vehicles, whatever the other benefits, will not allow us to travel significantly faster.

Besides, there is evidence that most of us have enough travel to meet our needs for access to people and places, employment, services and activities, family and friends, with an ensuing good range of opportunities and choices. For instance, a study by the former Competition Commission found that 80% of people living in urban areas had a choice of three or more large supermarkets within 15 minutes’ drive, and 60% had a choice of four or more. If a choice of three or four supermarkets is sufficient to meet your needs, your demand for travel to this class of destination is said to be ‘saturated’, a standard concept in business economics. This has come about through both the growth of car ownership providing access, and the supermarket chains taking advantage of road construction that made land accessible for new large stores both in and on the edge of urban areas, both trends now largely played out. Moreover, with the growth of local ‘convenience’ food stores in recent years, both branches of major chains and independents, a similar situation commonly applies in urban areas for those who shop locally.

Beyond food stores, DfT Journey Time Statistics for access to key services indicates high proportions of potential users having access to key services within reasonable travel times. For example, for access to GPs, 71% of users are within 15 minutes travel time by public transport/walking and 96% within 30 minutes, while 87% are within 15 minutes by bicycle and 98% by car. Similarly, high levels of access are found for other services, including employment opportunities, schools, food stores and town centres. Journey time statistics can also be used to infer levels of choice of such services. For instance, the populations of a majority of English localities have access on average to five or more GPs within a 30-minute journey by public transport/walking, and almost all localities have such choice within 15 minutes by car. Moreover, new methods for connectivity analyses are allowing even better understanding of these relationships between transport services and the facilities and services people need to reach (see for example https://www.podaris.com/ ).

More generally, the available evidence indicates that those with a car in the household, or who have the use of decent public transport services, as a result have good levels of access and choice of regularly used types of destination. There are, though, places where choice is limited, particularly in rural areas, which is where the car is particularly advantageous.

However, the population is growing, the consequence of net immigration. The impact on travel demand will depend on how this growth is accommodated: to the extent that new housing is developed on greenfield sites, car use will be important, leading to more traffic, and prompting further road investment; but to the extent that new homes are developed in existing urban areas, investment in public transport would be more relevant. This balance would be influenced by how demand for accommodation is influenced by the travel preferences of young adults. Yet the current bottom-up piecemeal approach to planning for new homes by each local authority, does not address the overall likely impact on the transport system.

Market maturity

The pattern of uptake of a new consumer item or service over time generally plots out as a S-shaped curve: slow growth initially driven by innovators who prize novelty or cutting-edge technology, followed by the early adopters, then the middle majority and subsequently by the laggards, in the well-known technology adoption life cycle. The eventual outcome is high levels of ownership and use, for instance over 85% of household ownership for many types of ‘white goods’, such as washing machines and refrigerators, and similarly for well established ‘brown goods’ such as televisions. When such high levels are achieved, demand is effectively saturated, with further sales dependent on technological advances where that is possible, prompting replacement, on obsolesce or excessive costs of repair, or on growth of households. Markets are then said to be mature.

Oddly, demand saturation and market maturity are concepts rarely considered in travel analysis. Although I published a paper in a peer-reviewed journal in 2010 titled ‘Saturation of Demand for Daily Travel’, few other investigators have pursued this theme. The general assumption is that travel demand will continue to grow as incomes grow, such that econometric analysis involves unquestioning extrapolation of historic data and relationships into the future, as the basis for forecasting of travel demand and appraisal of proposed transport investments

The evidence for substantial travel demand saturation is fits well with the familiar concept of sustainable travel, and prompts my proposal that transport networks are best regarded as mature, with only marginal benefits to be gained from costly investment in additional capacity. This is already how we see urban roads, where, in the last century, efforts were initially made in the 1950s 60s and 70s, to increase capacity to meet growing car use, for instance by constructing urban motor roads (often elevated), by creating one-way systems (known as ‘gyratories’), and segregating traffic from pedestrians. But within a couple of decades this was seen to damage the urban environment and subsequently there has been a reversal of priorities, making more road space available for bus and cycle lanes and for pedestrians.

So we now effectively treat urban road networks as mature, the aim then being to manage demand for vehicle travel, whether directly as through London’s congestion charge or Nottingham’s workplace parking levy, or indirectly by investing in alternative travel modes, particularly rail-based mass transit technologies that are faster and more reliable than cars, buses or taxis on congested roads, such as Manchester’s light rail system.

I suggest that there is now a good case for regarding the interurban road network as substantially mature, with little to be gained in general from constructing additional capacity. A very common situation is a major road in or near populated areas, with morning and evening peak congested flows. To the highways engineer, this is a prompt or opportunity to invest in additional capacity, whether by adding carriageway to the congested road or constructing a separate ‘relief road’, in order to alleviate congestion and hopefully to improve connectivity between cities, so boosting economic growth – motivations which politicians are generally pleased to endorse as delivering ‘solutions’.

However, the morning and evening peak flows indicate that the road is being used by commuters, who have alternative routes available. So, if the capacity of one route is increased and delays thereby reduced, commuter traffic will divert to that route, a process now facilitated by the wide use of digital navigation devices (commonly known as satnav) that indicate journey times by alternative routes. Increased commuter diversion pre-empts additional capacity intended for longer distance business users, including freight, on which the economic case for the investment largely depends. This is the basis for the maxim that ‘we cannot build our way out of congestion’, which we know from experience to be generally true.

There will be cases where road investment may be justified, for instance to make land accessible for new development, whether commercial or housing. But the decision needs to be made jointly by the planning authority, the developers and the road authority, with the developers contributing to the cost of the road infrastructure from which they benefit, rather than claiming that the new capacity is a benefit to the whole community. Moreover, all instances of investment to increase road capacity result in increased carbon emissions, both from road users and from the embedded carbon in materials, notably cement and steel – a further reason to regard the road network as mature and its expansion as problematic.

Road freight

My argument so far has concerned personal travel, including travel by car on business and for commuting, both purposes recognised by the National Travel Survey. Yet cars share the roads with freight vehicles, so we need to consider how the latter impact on the demand for road capacity.

For aviation, though there are dedicated freight services, passengers in the cabin and high value freight in the hold are complementary sources of revenues for the airlines. On the railways, passenger and freight trains are distinct, but must be managed on busy intercity routes to optimise overall performance. But on the roads, such management is not attempted – it is effectively a ‘free for all’ as to who gets to use the available capacity.

The Department for Transport has collected survey data on road freight carried by a stratified sample of heavy goods vehicles (HGVs), including tonnes lifted, tonne-kilometres moved and kilometres travelled; domestically, these were 3-5% lower in 2023 than 2022. UK-registered HGVs operating internationally lifted 12% less tonnes in 2023 than in 2022, and 30% less than the 2015-2019 average, reflecting a long-term decline over the past twenty years, in part a consequence of the 2008 recession and Brexit. The number of licenced HGVs in England has changed little over the past twenty years. So, we have seen no overall growth of HGV traffic in recent years, and have little expectation of future change.

In contrast, the number of vans (i.e. light goods vehicles, LGVs) increased by 70% over the past two decades (DfT data set VEH 0101). A pre-Covid-19 survey published by the DfT in 2021 found that total van mileage and van stock have increased in parallel in recent years, with little change in average mileage, although mileage varied with the type of use: in 2019-20, 54% of the van population carried equipment, tools or materials and was responsible for some 60% of total van mileage; 16% delivered or collected goods, responsible for about 25% of mileage; while almost 30% were used for private non-business use or for providing transport to others, responsible for 15% of mileage. Use of vans for private non-business use would be captured by the National Travel Survey.

On a typical day, half of all vans stayed local, within 15 miles of their base, just over one third travelled regionally, and 15% travelled nationally or internationally. Vans travelling locally had the lowest average annual mileage overall, at 7,600, while vans that travelled nationally had the highest average mileage at 26,300. Over two-thirds of vans travelled on local or rural roads regularly, with other main or ‘A’ roads also used regularly by 60% of vans. Fewer vans use dual carriageways and motorways regularly, with only 39% and 21% of vehicles using these roads 4 or more days per week, respectively

It may be supposed that factors contributing to the growth of van use include the increasing popularity of online shopping, and perhaps the shift in the structure of the economy from manufacturing to service provision. Also, there may be lifestyle changes amongst some previous car owners that prompt a switch to vans. Changes of this kind tend to have natural limits, although it is difficult to predict these in advance. Internet sales as a proportion of total retail sales increased steadily from 3% in 2006 to 22% in late 2019, then peaked at 38% during the coronavirus pandemic, reverting to around 26% post-pandemic, possibly now a stable level. More generally, increased distances travelled by vans bring the businesses that use them into increased competition with similar businesses based elsewhere, implying diminishing returns and hence limits to distances travelled.

So to summarise, we have broadly steady HGV numbers and use, contrasted with rapidly rising numbers of vans, roughly two-thirds the usage of which is for business purposes and one third used for private trips that would be captured by the National Travel Survey. What does this imply for the argument that we should regard the interurban road network as mature?

To put the growth of vans in perspective, in 2023 cars account for 76% of all motor vehicle traffic, while vans have become more important over the last decades, now accounting for 17% of all motor vehicle traffic. However, vans are used predominantly on local roads, where generally there is little possibility or intention to increase capacity. The lack of growth of HGV numbers and use does not support any general investment in interurban road capacity. And the small proportion of vans using interurban roads, as well as the uncertain prospects for growth, likewise do not make a compelling case for further such investment. Accordingly, treating the interurban road network as mature seems a sensible approach.

Against this background, a major issue for both the DfT and the new NISTA must be the successor, if any, to the costly second Road Investment Strategy programme (originally announced at £27 billion for 2020-25), particularly at a time of severe pressure on public finances. Besides, any increase in road capacity negates the requirement to decarbonise the transport system, both on account of increased traffic and hence vehicle carbon emissions, and the embedded carbon in cement, steel and other construction materials, and in equipment and vehicles.

The interurban road network needs to be well maintained and used efficiently. The wide employment of digital navigation serves to enhance efficient use by offering optimal routing that takes account of traffic conditions and other impediments to movement. It is to be expected that the generality of vans used for business purposes would employ this technology, which is free to access via a smart phone.

I would argue that what is now needed is for road authorities to concentrate on keeping the system in good order, well managed operationally, and recognise and take advantage of the impact digital navigation is having on driver behaviour on their networks.

What we do not need is a further major programme of investment to increase the capacity of motorways and major roads, with the futile aim of building our way out of congestion. The Department for Transport is currently reviewing its Appraisal and Modelling Strategy, which creates an opportunity to rethink its published Transport Analysis Guidance, to develop its application to the management of existing capacity, rather than to produce demand projections that underpin a predisposition to invest in new capacity, supported by unevidenced claims that this will magically unlock economic growth.

This blog post is the basis for an article that appeared in Local Transport Today of 22 January 2025.

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.

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 British government has long been keen on encouraging the prospect of what were initially known as ‘connected and autonomous vehicles’ (CAV). In 2015 it set up the Centre for Connected and Autonomous Vehicles to stimulate the development of the technology and steered funds into the sector via the Transport Systems Catapult. Typical of recent bullish statements by DfT ministers is this from Grant Shapps, when Transport Secretary, earlier this year:

‘The benefits of self-driving vehicles have the potential to be huge. Not only can they improve people’s access to education and other vital services, but the industry itself can create tens of thousands of job opportunities throughout the country. Most importantly, they’re expected to make our roads safer by reducing the dangers of driver error in road collisions. We want the UK to be at the forefront of developing and using this fantastic technology, and that is why we are investing millions in vital research into safety and setting the legislation to ensure we gain the full benefits that this technology promises.’

There’s no doubting the enthusiasm, but is this just hype, or is there a reality underpinning the vision? And what exactly is the vision anyway? It seems to be principally focussed on re-imagining the existing private car as a vehicle that no longer needs a driver behind the wheel, and which can whizz its occupants around in robotic mode, avoiding collisions and improving safety, whilst allowing the passengers to get on with other tasks, or simply enjoying the ride and the view – or maybe having a nap.

Trials of such driverless cars on public roads are taking place in a number of countries, mostly with a human ‘safety driver’ still on board, but this requirement has been dropped in some US and Chinese locations where traffic conditions are deemed favourable. Yet the prospects remain uncertain, so it is timely that the House of Commons Transport Committee has initiated an inquiry into self-driving vehicles.

I am specifically exploring here the prospects for such driverless cars ever becoming widespread, acceptable and effective in the foreseeable future. I’m not considering the possibilities of driverless multi-user pods or rapid transit buses on at least semi-segregated roads, where some deployment has already taken place. Nor do I discuss the scope for freight vehicles to operate in platoons on inter-urban motorways, where a recent UK trial found the hoped-for improvements in fuel use to be disappointing.

The government published a substantial policy document in August of this year entitled Connected and Automated Mobility 2025, jointly presented to Parliament by the Secretary of State for Transport and the Secretary of State for Business, Energy and Industrial Strategy.

Note that Automated has replaced Autonomous, perhaps reflecting a scaling down of expectation. Note also that Mobility has replaced Vehicles, hence CAM rather than CAV, a sensible but small generalisation. But note also the absence of reference to Connected within the new document: the whole emphasis is on automation of individual vehicles, with little mention of the possibilities of connectedness between vehicles. In this, the government is following the prevailing mindset of the automotive industry, tech start-ups as well as established vehicle manufacturers, who see autonomy easier to achieve than connectedness between vehicles of different manufacture and type.

The self-driving vehicle concept is seen as the application of CAM technologies with greatest commercial potential. But for deployment to happen, safety must be assured. So in 2018 the government asked the Law Commission to develop the legislative framework for a safety regime. The Commission’s final report, also published earlier this year, will be the basis of legislation that the DfT will bring forward.

Legal consequences

Because, to be useful, a self-driving vehicle will need to be able to drive itself for at least part of a journey, there are profound legal consequences. The human driver can no longer be the principal focus of accountability for road safety. Instead, new systems of safety assurance are needed, both before and after vehicles are allowed to drive themselves on roads. The legal framework has to cover both self-driving functions, where a user must be able to take over control when the vehicle cannot cope – for instance in poor visibility-  as well as more advanced automation when the vehicle is able to cope under all conditions.

The Law Commission proposes three new legal actors:

• Authorised Self-Driving Entity (ASDE) – the vehicle manufacturer or software developer who puts a self-driving vehicle forward for authorisation to the regulator.
• User-in-charge (UiC) – the human in the driving seat while the vehicle is driving itself, who can take charge if the self-driving function cannot cope.
• NUiC operator, a supervisory system responsible when there is no user in charge, to navigate obstructions and deal with incidents.

There will need to be regulators for new functions:

• Vehicle type approval.
• Authorisation to self-drive.
• In-use safety regulation.
• NUiC operator licencing.

The proposals of the Law Commission will need to be enacted in legislation, to make possible the government’s intention to make the UK an attractive place for the deployment of self-driving vehicles, even though the main development of the technology is taking place in the US, where there is considerable diversity of regulatory regimes across the states. However, the comprehensive legal framework may deter some prospective developers.

Ride-hailing operators such as Uber, who have aspirations for a driverless future, might hope to save the costs of the driver. But under the proposed regime they would need to own the vehicles and accept responsibility as the NUiC operator for oversight of operations, and possibly also to be the ASDE. This would be a large and costly change from the company’s current capital-light business model, where ownership of the vehicles lies elsewhere.

Electric vehicle maker Tesla’s approach to automation has meanwhile been to incorporate the hardware into existing privately-owned vehicles and to progressively improve the software over time to get to the point of implementing what is being marketed as ‘Full Self-Driving’ capability. Taken literally, this would also require Tesla to be licenced as a NUiC operator, with oversight of its whole fleet of vehicles on the road, which is hardly conceivable. So if they use the automated mode, Tesla drivers would need always to stay alert and be prepared to take charge in the event of the unexpected.

Safety

A key question in this discussion is the appropriate level of safety required for a self-driving vehicle. The Law Commission took the view that this is best decided by ministers, in the light of judgement of the public’s acceptance of risk. The view of the government, set out in the recent policy document, is that self-driving vehicles should be held to the same standard of behaviour as that expected in road traffic legislation for human drivers: ‘competent and careful’. This standard is higher than that generally enforceable now on the average human driver – who include, for example, drivers who are fatigued, distracted or under the influence of drink or drugs- despite this not being the behaviour that is expected of them.

The ‘competent and careful’ standard appears to be the minimum required politically. Anything less would hardly be publicly acceptable. But does it do the trick? On occasion, self-driving vehicles will inevitably be involved in crashes with fatalities. ‘Competent and careful’ implies that the self-driving vehicle could not be blamed. The fault would be attributed to the other drivers (‘human error’) or to vehicle- or road-related defects. Yet would it be possible to demonstrate such blamelessness in practice, when the other parties to the crash would be seeking to shift responsibility?

In Britain there is one fatality per 140 million miles driven, so deaths involving self-driving vehicles could be expected to be exceedingly rare events. But when they do occur, they will surely  attract much public attention. As a result, there may well be pressure to tighten safety standards further, which, done in response to public anxiety, may undermine the general acceptability of self-driving vehicles. There is therefore a good case for a higher initial safety standard than ‘competent and careful’ to be set.

Benefits

The practical development of vehicle automation for general deployment is proving more difficult than the pioneering technology optimists had hoped. Apart from getting the technology to the point of being publicly acceptable, there is an evident need to develop viable business models consistent with the expected regulatory regime. And that means asking who will buy the vehicles? This in turn will depend on how purchasers perceive the benefits. In this regard, the practical benefits of vehicle automation remain unclear.

Proponents point up the safety benefits, especially in the United States where almost 39,000 people were killed in motor vehicle crashes in 2020, a fatality rate of 12 per 100,00 population, compared with 2.3 for the UK. Given that human error and risky behaviour is said to be responsible for 90% or more of fatalities, it would seem a reasonable expectation that the ‘robot driver’ of a self-driving vehicle could do better than fallible humans. 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 negotiation that occurs between human drivers to settle which gives way when space is tight. Besides, the driving performance of a robot would need to be very similar- or better- than that of a human driver to ensure public acceptability. A self-driving vehicle that proceeded particularly cautiously to meet safety requirements could be unattractive to the purchasers, and an irritation to other road users . So the robot driver would effectively need to learn how to drive like a human.

Another claimed benefit is that automation might increase the capacity of existing roads by allowing these safety-conscious vehicles to move with shorter headways, that is, with a smaller distance between them than the recommended two-second 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 would seem likely to be possible only on roads dedicated to self-driving vehicles, since the presence of conventional vehicles, not to mention cyclists, motorcycles and pedestrians, would require standard spacing to be maintained. In any event, in line with current experience, any increase in capacity would be expected to attract additional traffic, so that long term congestion relief would not be expected.

Automation that allowed an increase in road capacity might anyway be of interest to a road authority, as a public benefit, but not to individual vehicle owners if they had to bear the cost of the necessary technology. Because self-driving vehicles would be capable of operating empty, for example when returning to base after dropping off the occupant, and thus not needing to pay to park, they could add to the traffic miles generated 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. All this is before any consideration of how they would be licenced and the fee, and/or any road user charges they must pay- whether the same as, or different to, conventionally driven vehicles.

Prospects

One obvious problem of driverless vehicles is how they can happily enter the vehicle population alongside conventionally-driven vehicles The prospects for widespread vehicle automation on existing roads with mixed traffic seem very uncertain. The driving task on motorways might be lessened in good visibility and in the absence of road works, but the driver would need to be immediately available to take control in adverse situations – and when going into general traffic. There are some low-speed environments that might accommodate driverless vehicles, including campuses, business parks and other new developments with extensive road space, and some such deployment has taken place; in these circumstances driverless shared-use pods could be a cost-effective transport technology. Yet it is hard to see driverless vehicles successfully negotiating historic towns and cities with complex road layouts, often narrow streets, extensive kerbside parked cars, cyclists and randomly moving pedestrians.

This impediment to automation in general traffic in urban areas is particularly relevant to the idea of driverless taxis that could be attractive to ride-hailing operators such as Uber, to avoid the cost of the human driver and spread the extra capital cost of the vehicle through intensive use. On the other hand, there would be the potential cost of ownership of fleets of automated taxis, rather than the current model of ride-hailing operators where drivers own their own vehicles. Besides, a driverless taxi system operator would need to exercise oversight of the activity of each vehicle in their fleet, to deal remotely with incidents and navigate obstructions, which would add to costs. It is certainly possible that the relatively unskilled human taxi driver in their own car may remain a lower cost option than the robot driver in a specially provided one.

The way forward thus remains unclear. Indeed, after more than a decade of development of autonomous vehicles, the early excitement and optimism have been followed by some disillusion as the problems of achieving and implementing an acceptably safe product have been recognised. The recent decline in the value of technology stocks and venture capital investments suggests that finance to support further development of vehicle automation may be harder to come by. Indeed, Argo, an autonomous vehicle tech start up funded by Ford and VW, is shutting down, evidence of uncertain prospects for the technology. Accordingly, it would be premature to predict the eventual outcome, both in timing and extent of deployment. Who can judge whether, as enthusiasts for the technology assert, children born today will not need to learn to drive a car?

The major transport innovations of the past have been those that made possible step-change increases in the speed of travel – the railway and the modern bicycle in the nineteenth century, the internal combustion engine for road vehicles and the jet engine for aircraft in the twentieth century. These step-change increases in speed, and thus reductions in journey times, permitted increased access to people and places, opportunities and choices, which were the benefits of harnessing the energy of fossil fuels for the motive power of mobility. In contrast, it is unlikely that automation would increase the average speed of travel on the existing road network, which is constrained by safety and congestion. Accordingly, the benefits of vehicle automation are much more likely to take the form of improved journey quality, and hopefully safety, and the possibility of doing other things whilst on the move – particularly those that have come with the digital information and communications era . It remains to be seen to what extent purchasers of driverless vehicles will be willing to pay for these benefits – or if they can achieve them by adapting to wider new mobility thinking in other ways, particularly at a time of changing inter-generational attitudes to the ownership of vehicles personally, and their use.

The UK government has been very supportive of vehicle automation, in particular aiming to put in place a comprehensive legislative regime based on the thorough analysis by the Law Commission. Yet there is only limited commercial development of the technology underway in Britain, so the benefits for both industrial and transport policy do not seem to be that great. A more important technology priority for road transport policy has surely to be the switch to electric propulsion and the quest for transport decarbonisation.

This blog is the basis for an article in Local Transport Today dated 14 November 2022.