TAPAS.network | 3 April 2023 | Commentary | Tom van Vuren
The Welsh Roads Review has been seen as signalling a radical new approach to road building, but to
it has really just been the application of good appraisal practice, as set out last year’s revised WelTAG guidance. The challenge now for transport planning professionals, he says, is to implement these new assessment principles in modelling a much-changed set of transport objectives, far from the old ones majoring on travel time savings and congestion relief
A GOOD DEAL of attention has been deservedly paid in recent issues of LTT to the report of the Welsh Roads Review Panel The future of road investment in Wales, the Welsh Government’s response to it, and the consequential political and professional reaction. I doubt the last word has been said about the decision to dramatically cut the existing roads programme, and to work to a set of clear conditions under which any new road building would be supported in future.
As a transport modeller, I have taken some time to read the report, the response and contributions by others in the transport planning profession. My conclusion is that the Welsh government’s response exemplifies not so much a radical change in their approach to scheme appraisal, but that they are determined to make best use of what their recently revised WelTAG assessment tool has been intended to achieve: a strong up front case for change in the early project planning phase, which subsequent business case analyses can then refer to and build upon.
As a reminder: the Welsh Government has said that it will only consider future investment in roads if projects meet the following criteria:
To support modal shift and reduce carbon emissions.
To improve safety through small-scale changes.
To adapt to the impacts of climate change.
To provide access and connectivity to jobs and centres of economic activity in a way that supports modal shift.
The intentions were largely signalled six months prior to publication of the Roads Review Panel report- and no doubt around the time it was being finalised – when the revised WelTAG was published as a consultation draft in August 2022. Much has been made of WelTAG’s framework of five planning stages, and particularly the stage 0 case for change. And even though those four government criteria are roads-specific, they illustrate the intention for stage 0 in the planning process well. I like the straightforward text in WelTAG; “Ultimately it explains why you need to do anything at all”. But forthright as it is, it’s not unique: The Department for Transport TAG guidance for the senior responsible officer identifies an up-front stage for option generation too, and I contend that in Wales roads should also remain options to be considered - even if they are later discarded for failing to satisfy the above four grounds.
I revisited the new WelTAG to see what else I like in it. It’s a good read, and not just for modellers! The term well-being is mentioned no less than 300 times, often linking back to the Well-being of Future Generations Act (Wales) 2015. And although WelTAG’s well-being dimension replaces TAG’s economic dimension in the business case, there are more similarities than differences. For example, many of the well-being components are the same as in TAG, can be quantified, and still “all transport projects, interventions MUST demonstrate how they deliver value-for-money”.
Another good observation in WelTAG is: “… transport planning is not an exact science. It is about designing good programmes and projects that meet the needs of people in Wales, not just adding up costs and benefits”. Numbers rather than people have unfortunately become the centre for debate, but benefit-cost ratios and well-being appraisal are not exclusive. I have argued elsewhere that BCRs have to some degree become victims of their own success. In the past considered too narrowly focused on traditional metrics related to transport efficiencies (travel times, operating costs, reliability, accidents), they have been extended over time to include, in addition, wider project and policy impacts, be they social, environmental or economic. Much academic work has gone into quantifying and also monetising those wider impacts. But an unintended outcome has been that, translated into pounds, they have become hidden in that single number that is the BCR.
Many of the Welsh government’s well-being objectives can potentially also be monetised, but the question is whether they should be. The government’s intention to produce benefit- cost ratios with and without travel time savings, is a good example of how the BCR is still a useful catch-all, but also that it is possible and desirable to separate out each of the contributing components. Even with a reduced emphasis on benefit-cost ratios, I hope that the next iteration of WelTAG provides advice on tools and data sets to use, and particularly when integrated well-being appraisal requires the analysts to assess impacts that until now have received less attention in application. Without that, I expect that practice will default to the existing TAG guidance, which would be an opportunity lost.
I worry over one particular input element to appraisal, and that’s when I see scenarios that embed ambitious government policy described as ‘committed’, without evidence how those commitments can be achieved. I understand why this concept is applied, but I’m uncomfortable, and when embedding uncertainty in decision-making the government’s uncertain ability to meet such targets should surely be a consideration
And even though it is WelTAG’s intention to rely less on formal modelling and appraisal techniques, the evidence used to support decision-making must remain robust. There is a danger that decisions will be influenced more by what planners might want to see happen, rather than what analytical methods tell us is likely to happen as a result of policy, planning and project interventions. Even a ‘decide and provide’ approach needs a ‘predict’ element to ensure that the measures taken are effective. In this regard the couplet ‘vision and validate’ seems more meaningful to me. In WelTAG words: “It is particularly important to support with good data, especially if you are not providing additional benefit-cost modelling”. One way for the Welsh Government to help practitioners to do that would be by producing a WelTAG databook, to ensure quality and consistency.
Without cost-benefit ratios, decision-makers must transform how they use the results from modelling, appraisal and other analytics and grow their confidence in decision-making under uncertainty. Here’s where the Welsh government can build on the good work that DfT has been doing in the development and promotion of the concept of Common Analytical Scenarios that provide a context for the consideration of different futures. What kind of scenarios will be appropriate in Wales?
I worry over one particular input element to such appraisal and that’s when I see scenarios that embed ambitious government policy expressed as ‘committed’, without evidence how those commitments can be achieved. I understand why this concept is applied, but I’m uncomfortable, and when embedding uncertainty in decision-making the government’s uncertain ability to meet such targets should surely be a consideration. When thinking about scenarios I like to refer to Transport for Scotland’s Stephen Cragg’s presentation in a recent Transport Planning Society webinar on future-proofing transport decision-making.
Stephen distinguishes three types of scenarios:
Predictive scenarios: what will happen given a set of assumptions
Explorative scenarios: what could happen given various uncertainties
Normative scenarios: what needs to happen to hit a target
Much of the recent debate on scenarios, including whether UK Government assumptions in the Transport Decarbonisation Plan are aligned with its decarbonisation commitments, has concentrated on predictive scenarios: assuming the levels of EV uptake and other measures to be sufficient to reach net zero by 2050. Such consistency is important, but certainly does not guarantee that the targets embedded in the scenarios are reasonable and achievable.
The DfT’s seven Common Analytical Scenarios are mainly explorative, aimed to equip the analyst with quantifications of probable and plausible uncertainty when projecting travel demand into the future. But what we as transport planners really need to provide, also in the context of the Welsh government’s intention to restrict future road building, are normative scenario tests: to provide evidence of the effectiveness of alternative measures to hit that net zero target These are more than alternative do-something cases to be tested – they must reflect realistic do-minimum futures with those interventions, and their expected outcomes, credibly represented.
How complex should these appraisals be? I welcome the Welsh Government’s WelTAG statement that for most projects in Wales it will be sufficient to use WelTAG Lite, giving confidence to promotors and their consultants that a simpler approach is often best. Although the proportionate approach underpins much of TAG, there has been a tendency in practice to play it safe, and to make modelling and appraisal more complex than has often been required. Guidance is needed on determining whether to follow the WelTAG Lite, WelTAG Standard or WelTAG Plus route. Rather than approaching the need for more or less intricacy on the basis of project costs, this should be done by an explicit assessment and reporting of the anticipated complexity of the responses to and benefits of a transport intervention (project, policy or programme).
If roads are mainly off the table, other modes need more scrutiny in appraisal. What needs to change in modelling, to focus planning and construction on sustainable alternatives, and how they may achieve the government’s wider objectives? Representing behaviour change is not just about choosing other alternatives in future, it’s also about reflecting a future necessary change in attitudes by the population, in personal, not government, valuations of these alternatives to roads.
This is of course a big ask: modelling is more of a science than an art. By calibrating models using observed behaviours and preferences we introduce objectivity and transparency – but the (implicit) assumption is that today’s behaviours can be transferred to the future. If the success of a net zero policy relies on people adopting low carbon behaviours, something needs to change. “If you keep doing what you’ve always done, you keep getting what you’ve always got”, is a truth worth remembering in this context. And so we must explore the full behavioural futurology landscape - not just in response to changing policy or financial (dis)incentives, but reflecting changes in attitudes, social and cultural norms. Perhaps ‘What-if’ tests may be the best we can do in this respect at the moment.
If there is for me one thing radical and game-changing about the Welsh government’s response to the Roads Review Panel’s report, it’s that I expect the number of future transport appraisals that mainly aim at quantifying transport outcomes to get less and less. There is a commitment to transport investments that support decarbonisation, transport policies that enhance inclusivity and well-being, rather than solve existing or anticipated congestion problems. This all means that travel time benefits per se will not be the main outcomes, but maintain relevance only where they act as the drivers of societal changes that are sought and should be made explicit in analysis. Will politicians and the public be comfortable with that new approach to transport decision-making? And are we as professionals ready to support its application?
References and Links
Tom van Vuren is Policy Director at the Transport Planning Society, Regional Director UK & Europe at Veitch Lister Consulting and a Visiting Professor at the Institute for Transport Studies at the University of Leeds.
This article was first published in LTT magazine, LTT866, 3 April 2023.
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