A change of direction: DecarboN8 informs the Welsh Roads Review Panel

By Greg Marsden

On 14th February the Welsh Roads Review Panel reported its recommendations to the Welsh Minister. The Review Panel had been established in September 2021 to review the strategic fit of the 51 roads schemes that were in the pipeline in Wales in the light of its climate change commitments and other policy priorities. The Panel was tasked with assessing the extent to which the schemes were necessary given the wider commitments to a 10% (per head of population) reduction in miles travelled by car by 2030 and the increase in public transport, walk and cycle from the current 32% to 39% by 2030 and 45% by 2040.

The Panel set out a series of principles which should inform the assessment of the need for road expansion. Cases which advanced safety, tackled climate vulnerabilities and constructed access roads to new development (which could also be well served by public transport, walk and cycle) were all likely to be consistent with policy.

In deciding what would not be consistent with current policy, the Panel drew on work by DecarboN8 looking at the whole life emissions costs of new infrastructure. Our work showed that there can be quite considerable CO2 emissions bound up in material extraction, transportation and construction processes. Over the next fifteen years or so, whilst vehicles are still predominantly fossil fuelled and whilst industrial processes are not decarbonised, the construction emissions cannot generally be offset by ‘smoother traffic flow’ as is often argued. As in our report, the Roads Review Panel also considered that many new road investments are developed with the intention of increasing vehicle speeds. Particularly with speeds above 55mph this can lead to quite significant increases in CO2 emissions from the air resistance that needs to be overcome.

The Panel came to the conclusion that, of the 51 schemes it was tasked with reviewing, only 17 met the criteria for being progressed. This is a major shift in approach, which recognises the importance of acting in line with the carbon budget commitments which have been set out. But it is also important in a couple of other regards. First, the outcome is not “no roads” but “fewer roads”. Whilst the outcome might be painted as anti-car, it recognises the realities of carefully targeted developments which can be consistent with overall policy goals. Second, the report is not a full-stop. As our research showed, the challenge we currently face is reducing emissions quickly enough to stick within the agreed carbon budgets. There is no headroom right now to encourage additional traffic growth or to absorb additional infrastructure emissions. However, in the next one to two decades, as more vehicles are zero emission and if new materials and industrial processes can genuinely be shown to be zero carbon, then the carbon arguments to expanding roads will diminish. Now, however, is the time to limit expansion and live within our carbon means.

It is interesting to see divergent approaches to roads investment being taken in Wales, Scotland and England. As yet, the DfT has not followed the lines of argument taken in Wales and Scotland on traffic demand reduction. The Transport Select Committee inquiry into Strategic Road Investment may touch on some of these issues. However, the early signs following the release of the National Road Traffic Projections in 2022 are that there will be pressure for continued road widening in England. The carbon implied in a mile of road and in a mile driven on a road are largely the same across the different nations in the UK. It seems that the politics of dealing with the implications of that carbon is what differs. The Welsh Roads Review Panel is a welcome reminder that not only are there different policy pathways that we need to follow to stick within our carbon budgets, but that there is a willingness in some places to embrace the sometimes difficult implications of changing to those new paths.

Read the Welsh Roads Review Panel’s report: The future of road investment in Wales

Read DecarboN8’s reports on Embodied Emissions and Transport Infrastructure

Read Greg Marsden’s written evidence to the Transport Select Committee on Strategic Roads Investment