DfT’s Science Advisory Council challenges planning status quo
The Department for Transport’s (DfT) Science Advisory Council (SAC) has published a paper offering an “independent perspective on science and evidence opportunities that encourage land use and transport planning decision-making.”
It has found that Local authorities’ presumption is generally in favour of replicating existing patterns of transport provision – implicitly prioritising car use over other passenger modes. Furthermore local highway and planning authorities are cautious about approving developments based on infrastructure that encourages movement patterns based on active travel and public transport, supported by high levels of digital connectivity.
SAC’s remit is to provide “strategic level scientific advice and challenge” to DfT and the paper is based on inputs from government officials and external experts including consultants, planners and sustainable mobility agencies with extensive experience in the area.
The paper concludes that meeting DfT goals may need a change in culture that better defines sustainability and better supports its delivery through re-framing and training for decision-makers, including the Planning Inspectorate.
The context for the work is that although academic and transport professionals have collectively recognised for over half a century the connections between land use and movement patterns of freight and passengers, the use of this evidence to inform planning decisions has been inconsistent and rather limited, with non-transport factors playing a more major role.
The summary of expert views reported in SAC’s paper, published by DfT, pulls no punches. For instance it states “larger housing developments can by many mobility measures be considered to be ‘in the wrong place’ from a transport perspective.
Often they are accessible only by car and provide limited opportunities for using other modes of transport that may be lower in greenhouse gas emissions or support public health through active travel. They may not support an ageing population where accessibility of local facilities and public transport becomes important to personal independence and quality of life.
“Developments often lack comprehensive internal pedestrian and cycle networks and may be poorly connected to high quality public transport services and regional cycle networks. The primary development goal is often to build houses, rather than to create communities with facilities close at hand.
“A broader, systems-thinking approach is now required, which starts with a comprehensive vision for a new development and then designs it to achieve the intended outcomes.”
The paper notes that there are few examples of new settlements in the UK that have been built fully on sustainability principles, including prioritising sustainable transport modes. There are however some international examples, such as Freiburg in Germany, where a major and sustained investment in public transport, walking and cycling has led to substantial reductions in car travel.
According to SAC, there is a clear need for better visibility of case studies showing what ‘good’ or ‘different’ looks like, with robust data on how design and planning subsequently influence travel patterns, lifestyles and more generally well-being.
Other evidence collected by SAC describes that where attempts have been made to provide good bus service or local facilities, these only become viable (and are introduced) after a substantial portion of the development has been occupied – by which time early residents have developed car-based living patterns.
The work also outlines how under the current system winning planning approval for most major housing developments requires substantial road building and/or junction capacity increases to meet the anticipated increases in car trips. These investments are generally hugely expensive (typically tens to hundreds of millions of pounds), but if some fraction of that investment was directed towards high-quality active travel, public transport networks and local community facilities then levels of car use could be substantially reduced and the net community benefits could be much greater.
DfT, the paper also reports, is currently developing a postcode-based connectivity tool for assessing/scoring the sustainability of a potential development site. This has the potential to provide a UK-wide self-consistent approach to considering the contextual accessibility of development and its potential for supporting different travel options.
The tool, together with local planning policies, could be used to enhance the sustainability of developments by encouraging developers to increase sustainable transport infrastructure within and around low-scoring developments. Alternatively, developments in high-scoring locations might be permitted to build at a higher density.
Scientific and evidence recommendations contained within SAC’s review include:
There is a need for more robust datasets collating evidence that shows the effects of building sustainable transport networks and local facility provision into new developments. These datasets need to include trip numbers, trip lengths and mode shares – plus wider health, social, economic and environmental indicators. Given the limited evidence available in the UK, data should be sought from international case studies. There is a need to build a wider evidence base of what ‘good’ looks like for a variety of contexts and scales, referenced to designs of new developments for car-independency that are shown to have been successful.
There is an opportunity to quantitatively evaluate how higher-density residential developments might play a role in supporting better quality public transport (including demand-responsive) services and a wider range of local community facilities. Evidence is needed to show how good planning and design can rise to the challenge of meeting residents’ needs (and allaying their concerns) and maximising the attractiveness of these developments.
The tools used to estimate the trip/traffic generation of new sites and larger developments (such as TRICS and NTEM) should be refined to reflect the connectivity and sustainable mobility provisions of a proposed development, and its likely impacts on travel patterns. This should be linked to the DfT connectivity tool and assessments made which take into account a much wider range of indicators, including a greater emphasis on carbon impacts. These analyses should be consolidated in a comprehensive transport impact assessment as part of the assessment of individual developments and local plans.
Further evaluation is needed of the current incentive structures that motivate the various actors to promote largely car-dependent developments and identify pricing or regulatory changes that would help align commercial interests with other objectives around public health, net zero and quality of life.
A study should be commissioned into the governance arrangements that underpin the land use planning process and its operation in practice, taking a broader systems view and accounting for the various private and public sector actors, at both local and national levels. The aim would be to identify barriers and conflicting pressures when trying to promote sustainable developments, including community facilities and sustainable transport networks.
The national planning policy framework should be reviewed to ensure it fully reflects the current science and evidence in support of delivering sustainable developments including recommending the DfT connectivity tool as a site-sifting mechanism; and ensuring that its wording empowers local authorities to reject schemes that do not fit the framework without the risk of losing at appeal.
Training using the latest data and evidence should be provided to enable important actors – in local and national government, the private sector and relevant agencies – to better address sustainability considerations and work collaboratively, along with the resources needed to support and promote sustainable developments that provide realistic travel choices.