The challenges of using evidence-based approaches to make effective transport policy

We know that walking and cycling are great ways to keep fit and prevent harmful pollution. Yet we also know that, for a variety of reasons, people aren’t always keen on them as a means of getting around. Sustrans is the charity that’s making it easier for people to walk and cycle. We're working with families, communities, policy-makers and partner organisations across the UK to encourage active travel.

We pride ourselves on basing our activities in support of active travel on a solid evidence base. We were very proud to have our work featured in a recent UN report as an example of good practice at the science-policy interface. But the connection between evidence, policy, and investment decisions in transport is sometimes hard to fathom.

Despite the strength of evidence on the benefits associated with walking and cycling (primarily relating to public health benefits of increased physical activity, but also in other areas such as reduced emissions, and improved air quality), it remains challenging to secure significant investment in active travel. The balance of policy and investment is heavily skewed towards ‘big infrastructure’ and technological innovation.

Some of the constraints that seem to dictate this poor translation of evidence into practice include: i) the limitations of cost–benefit analysis mechanisms; ii) too much faith in technological quick-fixes; and iii) the adherence to predict and provide policies. These constraints result in funding decisions such as a £15 billion Road Investment Strategy in England, whilst local streets receive very little funding for infrastructure that makes them better spaces for people to use.

In theory, UK transport investment decisions are made on the basis of economic appraisal and cost-benefit analysis. Newly published research on cost benefit analysis is clear about the gaps. Weaknesses in forecasting, disregard for benefit distribution and equity, and the application of dubious techniques (for example, valuing small time savings, and discounting) all bring into question the veracity of an approach that works within the realms of similar projects (for example, comparing one road scheme with another road scheme). But how does one treat a local walking and cycling network in relation to a road building scheme in this context?

The misplaced optimism in the technological quick-fixes of the future is also an area where huge evidence disconnects can be observed. A big part of the emphasis on investment in transport research and development is focussed on, for example:

  • Electric vehicles – without recognition that on the one hand carbon emissions from energy generation are displaced (from the tailpipe to the power station chimney) rather than eliminated, and on the other hand 45% of particulate matter from traffic comes from brake and tyre wear (as distinct from fuel combustion), so poor air quality remains an issue.
  • Autonomous vehicles – despite the lack of any evidence about either consumer demand or the impact on traffic patterns.
  • 'Mobility-as-a-service’ provision – with scant regard for the fact that for many companies entering the market are doing so with the object of consumer data harvesting, rather than through any concern about mobility and accessibility.

The major risk is that we lose sight of what might already be possible. A new paper from a network of European cities and regions cooperating for innovative transport solutions on the future for autonomous vehicles expresses concern about the social distribution of impacts, and also concludes that  “if a transport authority wishes to pave the way for fewer private vehicles, bold planning decisions could already be made today to accelerate the uptake and dependence on public transport, cycling, walking.”

The adherence to predict and provide policies is a further misguided constraint in transport planning. In crudest terms, we look at past travel demand patterns, and we assume that the future will need ‘more of that’. This disregards any possibility of change, whether it be travel demand management, changing lifestyle patterns (for example, fewer younger people than ever own cars or even driving licenses), or even technological shift. The current Roads Investment Strategy does not reflect Government policies on environment and public health, does not align with changing societal patterns, and largely ignores the possible future automation of the fleet. A recently published research paper goes so far as to question whether continued adherence to predict and provide reveals an underlying, if unstated “real policy of car provision … and is the result of the influence of a powerful roads industry lobby”, whilst also noting that road building has little impact on economic activity, and cannot be relied on to kick-start the UK economy.

The net effect of these constraints is an evidence-policy-investment disconnect.

This disconnect in transport policy plays out very emphatically in air quality, where contradictions across policy areas introduce the risk of overall policy failure: pollution policies are not effectively integrated; transport policies either disregard air quality implications or are too heavily focussed on distant-future technology-led solutions; and health policies are too heavily focussed on remedial ‘cure’ work, rather than prevention. The continued investment in road ‘improvement’ does not seem to align well with other aspects of policy on air quality.

These contradictions need to be resolved if we are to have a coherent transport strategy. The effective application of evidence is crucial in enabling this to happen. Sustrans believes that active travel should lie at the heart of that transport strategy.

Dr Andy Cope is the Director of Insight at Sustrans