The Greater Cambridge Partnership (GCP) arranged a Citizens’ Assembly, comprising some 60 representative members of the community, that met over two weekends to consider transport options that would reduce congestion, improve air quality and provide better public transport. The Assembly heard evidence on these issues from experts, both independent and staff of the GCP. I was present throughout as an expert advisor.  There was extensive discussion by small groups at tables, effectively facilitated by staff of Involve, a charity established to promote public participation in decisions. The GCP was at pains to avoid steering Assembly members to a preferred conclusion, which was achieved, in my judgement.

The context is that the GCP agreed a City Deal with the Coalition Government worth £500m over 15 years, aimed at tackling the transport requirements of a growing city. Cambridge has an historic city centre that constraints both property development and transport provision, so that new businesses, many spun out of university research, are located around the periphery. Travel across the city between homes and employment is impeded by the narrow street network. Cambridge has an effective dedicated north-south busway along a previous rail route, and further such routes are planned. But the problem of the congested centre remains.

The second weekend of the Assembly focused on practical measures, leading to voting on preferred options, the results of which have been published. There was strong support for closing roads to cars, to allow faster and more reliable buses and to encourage walking and cycling, as well as to reduce air pollution. There was also good support for road user charging, to raise funds to invest in public transport and active travel. There was less support for measures to limit or charge for parking, and relatively little preference for no interventions.

The Assembly also voted on a wide range of supporting measures. The most popular was to put in place a franchised bus service under the Mayor, like that operated in London, in place of the present privately operated buses.

Assessment

The conclusions of the Assembly were a sensible response to the travel problems experienced in Cambridge and the surrounding area – a policy package comprising revenue generated from motorists to support investment in public transport and active travel, plus more road space for these purposes. The GCP is likley to find it difficult to reject this outcome, not least because the funding from the Government comes in tranches that have to be justified by showing progress towards tackling the problems for which the funding was promised.

More generally, this experience indicates that a Citizens’ Assembly may be a more effective means of carrying forward policy in problematic areas, particularly where conventional consultation exercises are likely to stimulate more negative responses from those who believe they would be adversely affected while those who may benefit tend to stay silent.

Breaks in trend

The title of my new book, ‘Driving Change: Travel in the Twenty-First Century’, reflects both the observation that there have been important changes in travel behaviour as we moved from the last century to the present, as well as the possibility that new transport technologies will make a difference to how we travel.

We have nearly half a century of time series data from the National Travel Survey that shows little change in both average travel time (close to an hour a day) and trip rate (about 1000 a year). In contrast, the average distance travelled displays two distinct phases: growth from 4500 miles per person per year in the early 1970s to about 7000 miles by 2000, after which growth ceased. Most travel is by car, so, as expected, car use per capita ceased to grow at the turn of the century, which is also the case for other developed countries. Such cessation of growth of car use has previously been called ‘peak car’, but a better term would be ‘plateau car’ since there is little evidence of a decline in per capita distance travelled.

Growth in average distance travelled was a consequence of higher speeds made possible by the growth of car ownership, supported by road construction. The proximate cause of cessation of growth in car use was the cessation of growth of household car ownership, which increased from 14% in 1951 to 75% by 2000, after which growth ended. A number of factors contributed to the break in the growth trend of car ownership. Population growth in cities, where alternatives to the car are viable, reflected both a shift in the economy from manufacturing to services that tend to be located in city centres, as well as the attractions of city living for young adults, whether studying or in employment.

In successful cities, exemplified by London, car use has been constrained by the capacity of the road network while the travel needs of a growing population have been accommodated by investment in rail. Increasing population density shrinks catchment areas for retail businesses and public services, so making active travel and public transport acceptable alternatives to the car. Car use in London peaked at around 1990 when 50% of all trips were by car, subsequently falling to 36% at present, with the Mayor’s ambition to reduce to 20% by 2041. Increasing population density gives rise to agglomeration benefits – economic, cultural and social – such that declining car use is associated with increasing prosperity. Other cities have a choice: whether to accommodate the car on account of its attractions as a means of mobility; or whether to push back the car to encourage interactions between people.

While car use per capita ceased to grow at the turn of the century, rail passenger numbers went in the opposite direction, doubling over a 20 year period, a consequence of the growth of employment in business services in city centres, congestion on the roads, and investment in the railway by both the private sector train operators and the public sector Network Rail.

The breaks in trend in both road and rail use pose problems for modellers and forecasters. Such breaks reflect changes in travel behaviour, hence historic relationships (elasticities) cannot be assumed to apply. Moreover, the invariance in average travel time observed in the National Travel Survey findings indicates that the benefits of transport investments are not time savings as conventionally assumed. Rather, people take advantage of higher speeds to travel further, to have more choice of destinations, services and opportunities. In short, the benefits of investment are improved access, which is generally subject to diminishing returns. So the conventional four-stage transport model that generates time savings as the output in ‘do something’ cases does not validly represent the changes in travel behaviour that result from an investment.

A feature of travel in the twenty-first century is the impact of new technologies. What impact may we expect on travel by old-established modes of the rapidly developing, often disruptive, digital technologies? Four new technologies are available, or becoming so. Electric propulsion eliminates tailpipe emissions, good for urban air quality and mitigating climate change. Digital navigation can improve the efficiency of our travel and reduce uncertainty and anxiety. Digital platforms allow more efficient matching of supply and demand, exemplifies by ride-hailing taxis such as Uber. And autonomous vehicles may reduce costs for conveyances that otherwise would have a human at the wheel, but may add to congestion as unoccupied private cars make their way to where they are next needed.

The past transport innovations – railway in the nineteenth century, motorcar in the twentieth, modern bicycle in its heyday, motorised two-wheelers in low income countries today – all these allowed a step change in speed and hence in access. In contrast, the new technologies seem unlikely to permit faster travel. Accordingly, they will not be transformational for users, but rather offer incremental improvements to the quality of journeys.

We are therefore in a period of relative stability in respect of per capita travel, which innovative technologies seem unlikely to disturb.

This blog also appeared on the PTRC website.

 

An independent Commission on Travel Demand, funded by UK Research Councils, recently issued its report, based on evidence and expert advice. There is no single message, other than that there are more uncertain factors influencing travel demand than conventionally supposed. However, the report make ten sensible recommendations for better processes.

I was disappointed that the report did not consider two matters on which I had submitted evidence. One is that demand for any kind of product or service may saturate, that is, cease to grow once all needs are met. For instance, ownership of many household goods, such as washing machines, exceeds 90%, so that demand no longer reflects growing tes, but only replacement plus population growth. There is evidence consistent with saturation of demand for daily travel for many purposes. For instance, 80% of the urban population of Britain have a choice of three or more large supermarkets within 15 drive minutes of home, and 60% have a choice of four or more. If you have a choice of 3-4 supermarkets within 15 minutes drive, you may not be inclined to drive further to have a choice of a fourth or fifth, in which case your demand for travel to supermarkets is said to have saturated.

Second, given that average travel time has not changed for at least the last 45 years, as measured in the National Travel Survey, increased travel demand (distance per capita) must require faster travel. This is now hard to achieve, given high levels of car ownership and the limited scope for this to grow, plus a mature road network where congestion proves difficult to mitigate. We have High Speed Rail on the way, but rail is a minority of all trips, so HSR would be a minority of a minority, with little impact on average speed.

The travel time constraint, coupled with the speed constraint, means that travel demand per capita is unlikely to grow significantly in the future. Total travel demand will be driven by population growth, of course, although the pattern of demand will depend on where the additional inhabitants are housed: greenfield means more cars, urban at higher density implies investment in public transport.

Professor Peter Jones, my UCL colleague, has been leading an EU funded project concerned with urban mobility, past and future, in five Western European cities – Berlin, Copenhagen, London, Paris and Vienna. The report is now available, as is a short speech by Peter.

A trajectory is identified in which cities start by attempting to accommodate the car, see the difficulties in high density locations and so reallocate road space to walking, cycling and public transport, and subsequently move on to focus on place – the role of streets as public realm for non-mobility activities. The figure above shows how car use peaked and then declined in consequence.

Recognition of place as an important quality of urban streets presents a problem for conventional transport investment appraisal, which only recognises the economic benefits of increased mobility. The report advocates ‘vision and validate’ as an approach, as opposed to the traditional ‘predict and provide’, using cost-effectiveness analysis to justify investment to attain the desired balance between mobility and place.

This report is a valuable synthesis of a considerable amount of data and analysis highly relevant to how we think about the future of cities.

 

I have long been skeptical about the case for a third runway at Heathrow. The argument in favour concerns the growth of demand for business travel, yet most passengers at Heathrow are on leisure trips, so there is plenty of scope for increasing business travel by displacing leisure travel to other airports in the London area with spare capacity. In a blog posted in 2015 I suggested that Emirates Airline might fly from Stansted to its Dubai hub if demand for flights from Heathrow could not be accommodated.

I was therefore gratified to read in the Financial Times that Emirates is indeed launching next month a daily service from Stansted to Dubai. Other airlines are offering services from Stansted to New York: Primera Air and Wow Air. Stansted hosted 190,000 flights in 2017 but could accomodate 274,000 on its single runway.

Another stage on the long-running saga of expanding the capacity of London’s Heathrow Airport is marked by publication of a report from the House of Commons Transport Committee. This considers the Government’s Airports National Policy Statement, which endorses the proposal for a third runway at Heathrow. The Committee goes along with this, subject to quite a number of caveats about environmental impacts and costs.

What struck me were the weakness of the case for a third runway (the Northwest Runway, NWR), as revealed by the Committee’s findings:

Figure 3 on p17 shows that the main impact of the runway would be to increase the numbers of leisure travellers and international transfer passenger. The extra numbers of business travelers are very small, yet the case for the runway is mainly based on the needs of the UK economy.

‘The benefits and costs the NWR scheme are finely balanced. Even small changes in assumptions or methodology could mean that the monetised costs of expansion via a NWR would outweigh the benefits.’ (p19)

While Heathrow is ‘full’ in respect of aircraft movements and landing/takeoff slots, it is not yet full in terms of passenger throughput since each plane is on average only 76% full and is not always an  aircraft with the highest capacity (p40). Luton and Stansted have the equivalent of around one third of a runway to spare through to 2050. This means that passenger throughput for the London airports is forecast to rise by 27% out to 2050 without expansion at Heathrow (p42)

The forecasts  show that an expanded Heathrow would accommodate more than three times more outbound passengers than inbound passengers (p48), a net economic deficit to the UK.

The NWR scheme would only offer only one new destination to emerging and fast-growing economies when compared with no expansion by 2050 (p49).

Airport charges at Heathrow are the highest in the world (p82). Could a further runway be financed without increasing charges, which would erode the economic benefits and deter use?

Assessment

I am struck by the weaknesses in the case for building another runway at Heathrow. A key question for the future will be the ability of the airport to finance construction from private sector investors at a cost – both construction and financing – which the airlines and their passengers will be willing to pay via landing charges. The proposal may achieve planning consent but could prove to be commercially unviable.

Professor Anne Graham and I submitted evidence to the Transport Committee, which argued that the market for air may be more mature than generally supposed, and hence demand growth may be less than projected, with consequences for the business case.

 

I was recently involved, as a member of an expert Panel, in a study, Older Canadians on the Move, carried out by the Council of Canadian Academies. This had been commissioned by the Federal Government and focused on measures that might be taken to improve the mobility of older citizens primarily for longer distance travel, local travel being the responsibility of lower tiers of government. Nevertheless, we did recognise that longer trips started locally and so were concerned with door-through-door journeys.

The Panel identified three pathways to help facilitate door-through-door journeys for older adults and improve the inclusivity of the Canadian transportation system: advancing human and social resources; advancing technology and infrastructure; and advancing policy. Each pathway has an important research and development and innovation component, whether it be through the development of new technologies or the testing and implementation of research-driven solutions in real-world settings.

I have also contributed a chapter to a book edited by Charles Musselwhite on Transport, Travel and Later Life, on the topic Future Transport Technologies for an Ageing Society: Practice and Policy. Let me know if you would like to see this.

In recent years there has been emerging evidence that the travel behaviour of young people has been changing, characterised by a shift away from car use. The UK Department for Transport commissioned a thorough study from researchers at the Universities of West of England and Oxford, comprising a literature review and secondary analysis of existing UK data sets.

The trend for young adults to drive less than previous generations began approximately 25 year’s ago. Driving licence holding by people aged up to 29 peaked in 1992-94, while car driver trips per person declined by 36% between 1995-99 and 2010-14. This decline is attributed to a variety of social factors outside transport, including more participation in higher education, more lower paid less secure jobs, and delay in starting families. Within the transport sector, the high cost of car ownership and more use of urban  public transport have contributed to declining car use. There is inevitable uncertainty about the future, but the authors conclude that is is difficult to envisage realistic scenarios in which all these future uncertainties combine in such a way as to restablish earlier levels of car use.
US experience
A recent survey of younger people (‘the millennials’, ages 18-34) in California aims to identify the factors that explain why they are found on average to drive 18% fewer miles than members of the previous generation. One report addresses lifestyle and attitudes, a second deals with residential location. Generally, the findings of the UK and US studies seem consistent.

Charles Musselwhite has edited a new book on transport and travel in later life. I have a chapter on Future Transport Technologies for an Ageing Society. I discuss how the new digital technologies are affecting both the transport system based on civil and mechanical engineering technologies, and how we choose to travel. There are a number of ways in which innovations would be of benefit to those in later life, and a number of policy approaches that would help achieve such benefits.