Travel

Car useTransportTravel

This blog post is the text of an article in Local Transport Today.

Cycling is widely advocated as a desirable means of travel – healthier, cheaper, more environmentally friendly and barely slower than the car for short-to-medium length trips. The Government seeks a step-change increase in cycling with £2 billion new funding, as a cost-effective way of reducing transport carbon emissions.

Certainly, there is substantial scope to increase cycling by investment in better infrastructure, witness Copenhagen with dedicated cycle lanes on all major roads, where 28% of all trips are by bike, compared with 2.5% in London. So when, at the outset of the pandemic, the Mayor of London announced his ambition to increase cycling by tenfold, you could see that this should be possible with the requisite investment. However, when you’re in Copenhagen, you are aware of the considerable amount of general traffic (and viewing Scandi noir crime dramas set in that city, you see very few of the characters using a bike). In fact, with 32% of all trips by car, Copenhagen is only slightly less car-dependent than London with 35%.

Aside from cycling, the other big difference between these two capital cities is that public transport use in Copenhagen is only half that of London, 19% versus 36% of trips. This indicates that you can get people off the buses onto bikes, but that it is much harder to get them out of their cars, even in a small, flat city with excellent cycling facilities where almost everyone has experience of safe cycling. Yet we don’t want to diminish the use of buses, which are an efficient means of moving people in urban areas, the diesel engines of which can be replaced by electric or hydrogen propulsion. Fewer bus passengers mean less fare revenue and less frequent services.

Data for other European cities indicate that Amsterdam is similar to Copenhagen, with 32% of trips by bike and 17% by public transport. In marked contrast, both Zurich and Vienna have excellent public transport responsible for 40% of trips, with cycling accounting for only 7-8%. More generally, while the pattern of urban travel reflects both local geography and history, we don’t find cities in developed economies with high mode shares of both cycling and public transport.

In seeking to reduce transport carbon emissions, we should be careful not to underestimate the attractions of the motorcar, which is useful for longer journeys and for shorter trips with less sweat, for carrying people and goods, including child seats and the stuff left permanently in the boot. The car is well-suited for meeting our needs for access to people and places, for door-to-door travel where there is road space to drive without unacceptable congestion delays and the ability to park at both ends of the trip.

But there is more to car ownership than the ability to go from A to B. The growth in popularity of SUVs suggest that there are feel-good factors that motivate purchase of these costly vehicles (it would be interesting to see the findings of the market research carried out by the car manufacturers, regrettably proprietary). The fact that cars are generally parked for 95% of the time is a good economic argument for car sharing. But conversely, this also indicates the value we place on individual ownership, to have vehicle available when we want it, a vehicle that reflects our personal consumer preferences. Cars are not unique in this respect. My washing machine sits unused more than 95% of the time. I could share with others at the laundrette, but it’s more convenient to have my own.

Car sharing in its various forms is advocated as a means to reduce car use, road traffic congestion and carbon emissions. Sharing has been facilitated by online digital platforms, which have been transformative of many aspects of the economy. For travel, we have the disruptive impact of ride-hailing as exemplified by Uber, and of online booking of trips by rail and air. By contrast, the growth of car sharing has been relatively slow, indicating the development of niche markets, with substantial replacement of private ownership looking unlikely.

Where road capacity limits car use in city centres, both public transport and active travel are attractive alternative modes. Agglomeration economics have led to increased population density in successful cities, which shifts travel away from the car. The growth of higher education in urban centres has contributed to reduced car use by young adults.  However, these trends may weaken post-Brexit and post-Covid. And while car use can be impeded in low traffic neighbourhoods in favour of cycling and walking, the aggregate impact may not be great.

We need to be careful to avoid optimism bias when projecting the impact of measures to reduce transport carbon emissions. The models that are used for this purpose are complex and opaque, with many input assumptions and parameters to be specified. Optimism bias arises when modellers make choices, consciously or unconsciously, that tend towards achieving a strategic purpose. Yet optimism bias leads to outcomes that fall short of those that are forecast. 

It is now part of the culture of transport planning to place emphasis on the opportunities for promoting cycling. But caution is needed. When addressing the impact of changing mode share, attention should be paid to the modes from which the shift to cycling is expected. For instance, the well-established Propensity to Cycle Tool, which assesses the potential to increase the amount of cycling, assumes that commuters are equally likely to shift to cycling from any prior mode. However, the evidence from Copenhagen and elsewhere indicates that a shift to cycling from public transport is much more likely than from car use, which would substantially reduce the carbon reduction benefits assumed from boosting cycling.

If optimism bias informs assumptions about mode shift from cars to bikes, or about the scope for car sharing, then disappointment is likely to ensue.

Car useTravelUncategorized

Recent revisions to the road traffic statistics appear to show that there has been a substantial growth of motor vehicle traffic on GB minor roads in recent years, from 108 to 136 billion vehicle miles between 2010 and 2019, an increase of 26%. Traffic on major roads rose from 197 to 221 bvm over the same period, an increase of 12%.  (DfT Road Traffic Statistics TRA0102).

Road traffic statistics are based on a combination of automatic and manual traffic counts. Major roads are well covered in that traffic in all links is counted on typical days, although not every link in every year. Given the vast number of minor roads, however, it is only possible to count traffic at a representative sample of locations every year, and the observed growth is applied to minor road traffic overall. Estimates from a fixed sample may drift over time such that the sample becomes less representative of the changing minor road network. To account for any errors incurred in the fixed sample, the sample is revised through a benchmarking exercise every decade, involving a much larger sample of locations.

The most recent minor roads benchmarking exercise was published in 2020, based on 10,000 representative locations. Overall, the benchmark adjustment for 2010-2019 was 1.19, which is the factor to be applied to 2019 data from the original sample to bring this to the observed traffic level. Data for minor roads traffic for intermediate years are adjusted pro rata, to avoid a step change in the reported traffic data. There is significant regional variation in the adjustment factor, from 1.35 for Yorkshire to 1.09 for East of England, with London at 1.32. For B roads the factor is 1.25, for C roads 1.17; while for urban roads, 1.22, and for rural roads, 1.15. Applying the regional weightings yields an increase in traffic on minor roads of 26%, as noted above, whereas the increase based on the original sample would have been 6%.

The previous benchmarking exercise published in 2009 found a smaller overall adjustment factor of 0.95, with a regional range of 0.81 to 1.08.

The substantially greater adjustment required following the recent benchmarking, compared with the earlier exercise, suggests that there has been a real change in use of minor roads, beyond errors arising from drift in the sample. Importantly, had the increase in minor road use been spread evenly across the national road network, the traffic estimation based on the sample would have been close to that from the benchmark exercise. Hence the major difference between sample and benchmark indicates considerable heterogeneity of minor road traffic growth. Moreover, the fact that the sample failed to detect the traffic growth suggests either that the process for establishing the sample was deficient in some way, or that significant changes occurred in use of minor roads over a decade.

DfT statisticians have created a revised minor roads representative sample (4,400 locations) from the latest benchmark data, which will be used for the coming decade. It would be desirable to have comparative analysis of the previous and the new samples, to gain insight into what has been happening on the minor road network. Regrettably, the statisticians only report findings, and do not attempt to explain them, which leaves uncertainty as to the nature and cause of the reported changes to traffic volumes. The representative nature of the new sample must be questionable if the reasons for the failure of the previous sample to reflect reality are not understood and addressed.

Transport for London has recognised this uncertainty. The recent Travel in London Report 13 discusses the implications of the minor roads traffic correction (p92). The revisions mean that, for 2018, the DfT estimate of vehicle kilometres was 20% higher than previously reported last year (and included in Travel in London Report 12). The previous estimate suggested a fall of 1.8% in vehicle kilometres in London between 2009 and 2018, whereas the revised series now suggests an increase of 17.9% over the same time period, this change wholly arising from revisions to the minor road estimates. TfL notes that it is currently working through how the DfT have made this assessment, and also what this could mean for London data sets. For the moment, TfL is relying on its own traffic monitoring data, although it does not report traffic on minor roads separately.

The National Travel Survey could provide a cross-check on the traffic data. Average distance travelled by car/van driver decreased from 3388 miles per year in 2010 to 3198 miles in 2019, a decline of 5.6% (NTS0303). The GB population grew from 60.95m in 2010 to 64.90m in 2019, an increase of 6.5%. The net increase in car use of about one percent is inconsistent with the new road traffic statistics which show an increase in traffic for all roads of 17% over the same period. The NTS employs a fresh sample of respondents each year, so sample drift should not be a concern. However, it is not clear that the travel diary technique would pick up rerouting to minor roads, given that respondents are asked to provide their own estimates of distance travelled for each trip.

Possible causes of increase in traffic on minor roads

One factor contributing to the growth of traffic on minor roads is the increase in van traffic, including that arising from the growth of online shopping with home deliveries. The number of vans (light commercial vehicles) registered in Britain increased by 28% between 2010 and 2019. Total van traffic increased by 34% over this period, with an increase of 49% on urban minor roads compared with 10% on urban ‘A’ roads, although ‘delivery/collection of goods’ was less important in respect of journey purpose than ‘carrying equipment, tools or materials’. However, in 2019 van traffic amounted to 15% of traffic on urban minor roads, and 19% on rural minor roads, cars being responsible for 82% and 78% of traffic respectively. So, the growth of van traffic on minor roads is responsible for only part of the overall traffic growth on these roads.

Another possible explanation of the apparent large growth of traffic on minor roads is the widespread use of digital navigation (satnav) that offers routes that take account of traffic conditions and estimated journey times. Such devices make possible the general use of minor roads that previously were largely confined to those with local knowledge. This is likely to occur when major roads are congested and represents an effective increase in the capacity of the road network, so generating additional traffic – the converse of the ‘disappearance’ of traffic when carriageway is reduced. Increased use of minor roads is problematic when policy is concerned to decarbonise the transport system and to promote active travel, which these roads facilitate.

The possible role of digital navigation might be investigated by an analysis of the correlation of the upward adjustment factor for each minor road sample location with traffic volumes on nearby major roads – to test the hypothesis that there would be more use of minor roads in areas where major roads were most congested. If so, this factor should be taken into account when setting up the new minor roads sample for the coming decade.

The use of digital navigation has been growing and may continue to grow in the future. A better understanding of the phenomenon would be important for forecasting road traffic growth by means of the National Transport Model and models at regional level and below.

A further possible cause of the changed distribution of traffic on minor roads arises from intentional interventions aimed at reducing such traffic. It has long been the practice to discourage ‘rat running’ on urban minor roads by means of suitable physical control measures, as are used in low-traffic neighbourhoods (LTN). Such measures would reduce traffic in certain locations while possibly increasing it in others through diversion. Some locations in the minor roads sample may be so affected. If LTNs and similar measures increase over time, the sample may become increasingly unrepresentative, a factor that should be taken into account in setting up the new sample. However, the net effect of intentional interventions would be to reduce traffic overall, so this cannot account for the reported growth of traffic on minor roads.

The growth of minor road use by through traffic apparently facilitated by digital navigation would strengthen the case for implementing LTN measures. Alternatively, or additionally, the providers of digital navigation might be encouraged to omit routes that direct through traffic along minor roads.

More generally, the impact of digital navigation on the functioning of the whole road network seems likely to be significant and therefore worthy of investigation.

The above considerations prompt a number of questions:

  1. How reliable are the statistics for motor vehicle use of minor roads, given the apparent sensitivity to the sampling of locations?
  2. How reliable are the NTS findings for car use?
  3. What information is available on the likely causes of the increase of traffic on minor roads?
  4. What is known of the impact of digital navigation on the road network?
  5. What are the implications of digital navigation for transport and traffic modelling?

Summary

The reported increase in motor vehicle traffic on minor roads over the past ten years is substantial and locationally heterogenous, for reasons that are unclear. This lack of understanding raises methodological questions about the sampling of minor roads. The reported increase in traffic is not consistent with the findings of the National Travel Survey, as well as being of concern to Transport for London. While interventions to reduce traffic on urban minor roads may increase the heterogeneity of the sample, they would not increase the volume of traffic. Hence this increase is most likely due to the growing use of digital navigation devices that allow minor roads to be used by those without local knowledge. This has implication for transport modelling as well as for policies to decarbonise the transport system and encourage active travel.

This blog post is the text of an article published in Local Transport Today 19 March 2021

Car useEconomicsPublished papersTravel

I have a new paper on how time constraints affect our travel behaviour. The link to the journal is here. Some copies are free to download here. The manuscript is here. The abstract is below.

Considerable observational evidence indicates that travel time, averaged across a population, is stable at about an hour a day. This implies both an upper and a lower bound to time that can be expended on travel. The upper bound explains the self-limiting nature of road traffic congestion, as well as the difficulty experienced in attempting mitigation: the prospect of delays deters some road users, who are attracted back following interventions aimed at relieving congestion. The lower bound implies that time savings cannot be the main economic benefit of transport investment, which means that conventional transport economic appraisal is misleading. In reality, the main benefit for users is increased access to desired destinations, made possible by faster travel, which is the origin of induced traffic. Access is subject to saturation, consistent with evidence of travel demand saturation. However, access is difficult to monetise for inclusion in cost-benefit analysis. Consequential uplift in real estate values may be a more practical way of estimating access benefits, which is relevant to the possibility of capturing part of such uplift to help fund transport investment that enhances such access.

Car useTravel

The Department for Transport has initiated an exercise to assess how the transport system could be decarbonised, in line with the Government’s commitment to a net zero carbon target for the whole economy by 2050.

I have submitted some thoughts on behavioural aspects, including the scope for increasing active travel, decreasing motorised road travel and air travel, and the need to improve modelling to accomodate such behavioural changes.

Metz-decarb-26-5-20Download
TransportTravel

The Secretary of State for Transport has announced £2 billion of investment to boost cycling and walking in response to the Covid pandemic. The Mayor of London has plans that he hopes will increase cycling ten-fold and walking five-fold post-lockdown. These intentions take advantage of current public health constraints on use of public transport and are certainly praiseworthy, but there are serious questions about feasibility.

Increasing cycling in London ten-fold would take its share of trips to that found in Copenhagen, where there are segregated cycling lanes on all roads with significant traffic. Moreover, the city is relatively small, such that you can cycle from the centre to the edge in an hour or so, as I have done but would not attempt in London. However, car use in Copenhagen is only slightly less than in London, while public transport mode share is half that in London. This indicates that you can get people off buses onto bikes, which are cheaper, healthier, better environmentally, and no slower in traffic than public transport. But it seems more difficult to get people out of their cars, even in a city where virtually all motorists have current or past experience of cycling. And a decrease in users of public transport, while helpful while the pandemic lasts, would lead in the longer term to loss of fare revenue and of level of service.

Transport for London (TfL) analysed cycling potential in 2017, considering which trips by motorised modes could reasonably be cycled, mainly taking into account trip length. If achieved in full, cycling would be responsible for 40% of all trips, which would be consistent with the Mayor’s ambition. However, a large proportion of potential cycling trips are currently done with at least one other person, which would limit switching. Beyond that observation, considerations of behaviour change and public acceptability were not taken into account.

Boosting walking five-fold is even more problematic, to say the least, given that its mode share of trips in London has long been stable at 25%. Some modest increase in the near term is likely as people avoid short bus journeys. Perhaps the Mayor has in mind to increase the distance walked per trip, which again is likely to some extent in the near term. Yet walking is the slowest mode of travel and time available for travelling is always a constraint. A TfL analysis of walking potential in 2017 estimated that there are more than two million potentially walking trips in London per day, compared with just under one million at present, but most potential walking trips could also be cycled. So it is very hard to see how a five-fold increase in walking could be achieved, even before we consider behavioural factors, in particular the reasons why so many people prefer to drive rather than walk short journeys.

To see if the Mayor’s ambition is realistic, we need a full analysis from TfL, taking into account behavioural aspects, including travel time constraints, and avoiding double counting. It also needs to show that the cost of new cycling infrastructure to meet objectives is affordable, given the current loss of revenue, and to recognise the implications for public transport of the longer-term loss of fare income.

This blog post also appeared as a letter in Local Transport Today 29 May 2020.

TransportTravel

The Covid-19 epidemic has prompted discussion of the implications for travel behaviour once it is over. Will the recent downward trend in trips to work and for shopping accentuate? Might people prefer their cars and bikes to travel on crowded public transport? Will there be a bounce back in leisure air travel? All is speculation at present.

More immediately, we see that the new highly infectious virus has prompted huge and rapid global efforts of technological development: tests for the virus and antibody, and novel vaccines. The epidemic has also stimulated extensive efforts to model the consequences, modelling that is open, transparent and collaborative, and that has proved crucial in informing government decisions, in particular to see how new technologies can lessen the need for social distancing.

There are lessons for the transport sector, for which the main priority must be decarbonisation to achieve the government’s net zero carbon target by 2050. Technological development should be stepped up in the areas of batteries for surface transport, and new propulsion technologies for aviation and marine. Electric charging infrastructure needs to be made generally available to stimulate the purchase of electric vehicles.

The models employed in the transport sector are neither open nor transparent. They are obsolete in that they were developed well before current concerns with carbon emissions and are deficient in predicting observed outcomes. We need a new generation of travel/transport models that are open, transparent, and possibly crowdsourced, to inform decisions on policies for decarbonisation, including how new technology can complement behavioural change.

Transport decarbonisation is the top priority. In contrast, automation is not important. As I argued in my recent book, Driving Change, autonomous vehicles will be difficult to deploy on the existing road network, and the benefits are quite limited. It is for the car industry to develop automated features if it thinks that customers might purchase such vehicles. It is for governments to put in place suitable regulatory regimes. But it should not be a priority for governments to support the development of the technology, which would be a distraction from decarbonisation efforts.

This blog post appeared also as a letter in Local Transport Today 17 April 2020

 

 

 

Car useTravel

The Department for Transport’s (DfT) second Road Investment Strategy (RIS2) was published at the time of the recent Budget, committing to spend £27.4bn over the next five years on the strategic road network (SRN). The stated main priority is to maintain the existing roads. Only where existing roads are ‘simply not up to the job’ is the Government asking Highways England to develop wider, realigned or, in a few cases, wholly new roads to keep people and goods moving. Yet expenditure on maintenance is expected to be £12bn, whereas capital enhancements are worth £14bn.

Investment

Prioritising investment is based on the 2018 Road Traffic Forecasts, projecting growth on the SRN in the range of 29% to 59% by 2050. This suites the civil engineers of Highways England who see their main purpose as building roads. However, as I have argued previously, the DfT traffic forecasts are very problematic and have generally proved to overestimate outturn traffic levels. Moreover, as I noted in chapter 2 of my recent book, the rate of addition of lane-km to the SRN in recent years has been less than the rate of population growth, despite the high levels of spend.

It is therefore not surprising that average delays on the SRN have worsened during the RIS1 period, growing from 8.9 seconds per vehicle mile to 9.5 seconds per vehicle mile. The DfT’s ambition for performance at the end of RP2 is to be no worse than at the end of RP1. This is a very modest aspiration, and contrasts with the aim of the previous road investment strategy (RIS1) of a free-flow core network with mile a minute speeds increasingly typical.

The new ambition is consistent with the document’s recognition that it is ‘widely accepted that it is not possible to outbuild congestion across the whole of the road network’. Accordingly, investment is to be focused on congestion hotspots, so that average network performance will be at least as good in 2025 as it is in 2020. Yet, as I have pointed out, adding capacity induces more traffic, so tackling congestion hotspots has little impact beyond perhaps shifting congestion to another part of the network.

Optimisation

One odd feature of this and similar publications of Highways England, is the disregard of digital route guidance (Google Maps, Waze and others) that is in very wide use by drivers, because they find it of benefit in optimising routes under congested conditions and in estimating journey times. Roadside variable message signs are an outmoded technology, providing too little information, too late to be of much use.

There is picture of a route guidance app on page 38 of the RIS2 document, but no mention of its relevance. There is a statement that ‘During RP2 Highways England will work with Transport Focus [a consumer body] to investigate future opportunities to make more granular information about delay on the SRN publicly available. We anticipate that this might include reporting on a regional basis, journeys between conurbations, and maps showing delay across the network on a link-by-link basis.’ Highways England seems totally out of touch with the real world.

Non-investments

The RIS2 mentions the outcome of a number of earlier ‘strategic studies’ that now seem unlikely to lead to much. For the M60 Manchester NW Quadrant, it is concluded that the transformational options identified by the study would have significant adverse impacts on local people and communities, and overall would not provide value for money. The proposed Trans-Pennine Tunnel, improving the route between Manchester and Sheffield, seems unlikely to proceed. The Oxford to Cambridge Expressway project has been paused to look at other options.

In contrast, the A303 Stonehenge Tunnel is to go ahead. Yet the National Audit Office found that transport and economic benefits accounted for only 27% of total benefits; the value of cultural heritage, based on a survey asking people what they would be willing to pay to remove the road altogether, was put by the DfT at 73%, and yet this yielded a benefit-cost ratio of only 1.15 , which in the event is likely to be worse because cost overruns. The NAO noted that the DfT has no plan for the corridor as a whole, and that all the other projects on the route offered poor value for money.

This critique of the A303 route can be generalised to the RIS2 as a whole. Although it is entitled a ‘strategy’, in reality it is a construction programme that is deficient in both economic justification overall and indication of spatial impact of economic benefits. What benefits might we expect, and where? We are not provided with more than vague aspirations.

 

 

 

 

 

 

 

 

 

Travel

The Court of Appeal has upheld a challenge to the decision to proceed with a third runway at Heathrow airport on the grounds that the Government’s Airports National Policy Statement (ANPS), which endorsed the runway, was unlawful in failing to take into account the Government’s commitment to the provisions of the Paris Agreement on climate change.

The Government takes the view that Heathrow expansion is a private sector project and so will not appeal against the judgement, leaving open the possibility of later amending the ANPS. This doubtless suites the Prime Minister, who represents a West London constituency under the flightpath and who had earlier been a vocal critic of the airport’s expansion. Abandoning the third runway would also add to the Government’s credibility when hosting the COP26 climate change conference in Glasgow later this year. Meanwhile, the owners of the airport must decide whether an appeal to the Supreme Court would be worthwhile.

The case for increasing the capacity of Heathrow, the UK’s main hub airport, has been based on the needs of business: more direct connections for exporters, facilitating inward investment to the British economy, and boosting London as a world city for doing business. There is no convincing argument for expanding tourism, inbound or outbound, given the need to reduce carbon emissions from aviation.

What is generally overlooked is that most air travel is for leisure purposes. Even at Heathrow, only 25% of passengers are on business trips. So there is ample room for business travel to grow if the demand emerges. Leisure travellers would be displaced to other airports with spare capacity, Stansted and Luton near London, and regional airports beyond. This would happen under the influence of market forces since most business travellers would be willing to pay a premium for the advantages of Heathrow.

Suppose I need to travel to India, to Bangalore for instance. If I’m on a short business trip paid for by my organisation, I’ll fly direct from Heathrow. But if I’m going on holiday, paying out of my own pocket, I’ll shop around for a low-cost flight, expecting to fly with one of the Middle East-based airlines, changing flights at an intermediate hub such as Dubai. I might leave from Heathrow or from Gatwick, Stansted or a regional airport, depending on price and convenience. If demand for business travel to Bangalore grows, leisure travellers who might have flow direct will be have viable alternatives.

Ultimately, growth of demand for air travel will be constrained either by airport capacity or by the need to limit carbon emissions to comply with the Government’s legally binding target of net zero emissions by 2050. One way or another, the cost of air travel is likely to rise, reducing growth in demand.

Hubbub, a UK environmental NGO, has released a report on flying by people in the 20-45 age group, based on a survey sample of two thousand. It found that no less than half the flights by men aged 20-45 in 2019 were for stag parties and a third of flights by women were for hen dos. Hubbub is concerned about the carbon emissions from these flights and the options for reduction by selecting a UK destination. For example, swapping Barcelona for Brighton is the equivalent of going vegan for 2.5 months.

The high proportion of flying for partying is surprising, and reflects the availability of low-cost flights outside the main season for tourist travel. Some increase in the cost of leisure air travel would increase the attractions of domestic destinations, without rather little loss of enjoyment, I anticipate.

Although the private sector operator of Heathrow has a natural commercial interest in expanding its capacity, not all the airport’s users agree. Willie Walsh, chief executive of British Airways’ parent company, has been critical on account of the likely need to cover the cost of construction through higher landing charges. A capacity constraint would allow BA as the dominant airline to raise prices over time, but would also allow the Government to claw back some of the increased profits through a rise in Air Passenger Duty.

In short, we can manage without a new runway at Heathrow. The market will allocate airport capacity to the highest value users, and the UK’s chances of meeting its carbon reduction target will be improved.

Note added: The Supreme Court upheld an appeal by Heathrow Airport against the Appeal Court’s decision, so the new runway is not legally prevented from being built.

Travel

The environmental charity Hubbub has released a report on flying by people in the 20-45 age group, based on a survey sample of 2000. It finds that half the flights by men aged 20-45 in 2019 were for stag parties and a third of flights by women were for hen parties. Hubbub is concerned about the carbon emissions from these flights and the options for reduction by selecting a UK destination. For example, swapping Barcelona for Brighton is the equivalent of going vegan for 2.5 months.

An implication of this high proportion of optional leisure flights is to weaken the case for additional runway capacity to accommodate the forecast growth of demand for air travel, in particular the third runway planned at Heathrow. In the absence of increased capacity, growing demand would lead to higher prices in the market for air travel, which would tilt the balance towards UK destinations for leisure trips, to the benefit of the economy of seaside towns and other hospitable destinations. Most air travel is for leisure purposes. There is plenty of airport capacity for business travellers who are willing to pay a premium to command priority over those on leisure trips.

Car useTransportTravel

Transport for London has recently published its latest report on Travel in London. At 279 pages, this latest in an annual series is almost certainly the most detailed account of travel behaviour in any city in the world. All credit to TfL.

Table 2.3 shows trip-based mode share. Private transport (very largely car) was responsible for 48% of trips in 2000, declining to 37% in 2015, but thereafter stabilising. Public transport has been stable at 35-36% of trips since 2012, and walking at 24-25% since 2000. Cycling grew from 1.2% in 2000 to reach 2.5% 2018. So the declining trend of car use has ceased in recent years, but it may resume as new rail capacity is opened, particularly Crossrail (the Elizabeth Line). Nevertheless, the target reduction of private transport to 20% by 2041, a feature of the Mayor’s Transport Strategy, looks difficult to achieve.

Section 9.7 discusses the role of licenced taxis and private hire vehicles (PHVs), a topic of much current interest. Taxis (black cabs) have been in slight decline while PHVs have grown substantially in recent years, largely reflecting the entry of Uber into the market. A survey of PHV users in London found that the two main trip purposes were for a night out and to/from airports, but only 28% of PHV trips were for both outward and return legs. App-based PHV users were attracted by specific features: estimate of fare, time for driver to arrive, knowing details of car booked, and estimate of journey time. 30% of PHV users said they had not needed to buy, replace or own a car, which facilitates a shift from individual car ownership.

Assessment

While a long-term target for reduction in car use has merit in that it shapes shorter term decisions, no Mayor is likely to hold office for anything like the time to reach the 2041 target date. A shorter-term target would allow performance to be held to account. And while the recent experience of London is that a steady reduction in the share of trips by car is compatible with the economic, cultural and social success of the city, sustaining this in the longer term would depend on substantial investment in the rail system that provides a fast and reliable alternative to buses, cars and taxis on congested roads. The biggest challenge for TfL and the Mayor is to find means of financing this investment.