The response is centred upon issues we consider important to be accounted for in appraisal, modelling and evaluation and which may need further attention as part of the new AMES.  

Valuing costs and benefits – The valuing of travel time savings has been subject to ongoing challenge and review over a period of decades, reflective of its complex nature. Given the extent of influence this can have on the overall merits of the economic case for a scheme, we consider that this may once again need attention. Such attention is not so much about revisiting the specific values of time savings by mode. Rather, we are concerned that too much attention is being placed on direct economic benefits from time savings with insufficient attention being given to how slower journeys may indirectly accrue economic and social benefit. Such benefits may be in terms of modal preferences that result in more physical exercise.  Increases in active travel can have positive benefits for NHS and social care costs[1] by reducing morbidity (inactivity related ill health) for the UK population[2].  Active travel can also reduce mortality i.e., premature death and the subsequent loss of economically active years.  It also encourages road user behaviours that foster improved safety^[3] (that in turn may further affect travel choices and related economic and social outcomes).

Another consideration is the lack of analysis and monetisation of reliability. Whether it be for freight deliveries (for which financial penalties are often incurred), or for other modes (continuity of cycle paths) or improved interchange between modes, reliability is a much quoted value by transport users that our appraisal methods do not adequately capture.

Digital connectivity – Behaviour changes over the last 20 years have been considerable in terms of trip rates per capita across trip purposes. The impact that digital connectivity has had and will have in people’s lives looking to the future cannot be ignored. Digital connectivity helps in turn to unlock digital accessibility – the ability to reach employment, people, goods and services without direct recourse to travel. Is digital accessibility being adequately accounted for in modelling and appraisal in terms of its direct and indirect effects on the nature and extent of economic and social activity? Does existing transport analysis guidance support examination of the role of digital accessibility as part of scheme option generation and in turn assessment? The emergence of Triple Access Planning[4] as a vision-led access-focused approach to planning suggests this may be an area of importance for the new AMES.  CIHT also notes there is the issue of digital accessibility and the exclusion of some sections of society who neither have the skills nor the access to digital options thereby becoming excluded from society.

Accounting for diversity and equity – As an Institution, CIHT has emphasised in its technical reporting and manifesto, the importance of a transport system fit for all – recognising the diversity of circumstances and needs across the population of prospective transport system users. Such diversity includes accounting for travel purposes not necessarily given due attention to date, for example travel in the course of caring for others. Benefits as well as negative externalities from transport investment can be unevenly distributed and in ways that could be inequitable[5].

CIHT is aware TAG provides guidance on undertaking a distributional impact appraisal to capture how a scheme has differential impacts across transport users and the wider population; however at present this does not seem to have a significant impact on business cases.  We would welcome better insight from DfT as to the extent to which existing appraisal, modelling and evaluation is, or is capable of, examining and valuing the nature and extent of changes to the transport system in terms of population diversity and equity considerations.

Housing priorities - There is a growing concern that housing developments are often planned and delivered in locations poorly served by sustainable transport, leading to increased car dependency and undermining climate and social equity goals. We are not convinced that the current appraisal system adequately accounts for the long-term consequences of placing housing in unsustainable locations. Appraisal should help support decision making that integrates wider government priorities, including delivering new housing, delivering the industrial strategy, improving health, and supporting educational opportunities, ensuring that transport investment decisions support place-based planning and accessibility. To what extent this does or should fall within the DfT’s remit may be important to consider – linked to earlier reference to Triple Access Planning and the need to bridge between treatment of the transport, land use and telecommunications systems.

Climate action – In the recent work of our Institution on climate change and climate action[6], highways and transportation professionals highlighted concern about the extent to which existing appraisal guidance and practice is keeping pace with climate action requirements (including those addressing adaptation, resilience and biodiversity as well as decarbonisation). We would welcome greater efforts to ensure that appraisal processes and guidance are capable of appropriately reflecting and accounting for climate change and climate action in terms of costs and benefits. We note that such issues were also raised by the Road Investment Scrutiny Panel in 2023[7].

Accommodating uncertainty – The existing AMES (published in April 2019) prioritised the need to better reflect uncertainty over the future of travel in the analysis being passed on to decision makers. The Uncertainty Toolkit and Common Analytical Scenarios have emerged as a result: internationally groundbreaking work in breaking new ground. In the context of a world that has seen dramatic and unanticipated developments since 2019, including COVID-19 and geopolitical instability it remains unclear how well understood new approaches to accommodating uncertainty are and how effective they are proving to be. Uncertainties are social, technological, economic, environmental and political and can together have potentially major consequences for appraisal and advice to decision makers. Such consequences in their magnitude may overshadow other aspects of modelling and appraisal yet with the latter receiving greater attention. We would be concerned if uncertainty doesn’t remain a priority for the DfT in the new AMES.

Modelling network resilience – The efficient performance of transport infrastructure is not only important during normal operational conditions, but it is even more relevant during the occurrence of emergencies. We consider that the new AMES should give clear guidance on how to model travel appropriately during emergency situations, allowing the sector to understand and highlight the criticality of certain parts of the transport network that might not be prioritised for investment based only on normal operating conditions. This ultimately will improve the resilience of the transport network to different types of shocks and support appropriately communities during emergencies.

Guidance versus practice – The very nature of guidance is that it incorporates scope for interpretation in its application. It would be helpful to better understand how variable - in nature and quality - the application of existing transport appraisal guidance is. The Wales Roads Review process has been an example of where scheme appraisals have been examined by a third-party group, bringing scrutiny to the application of guidance. Perhaps such an exercise might be informative to an ongoing effort to ensure ‘fit for purpose’ guidance and its application? Wales has also reviewed its guidance, WelTAG[8] (that places more emphasis on wellbeing) and Scotland has STAG[9].:  CIHT encourages developments in appraisal in Wales and Scotland to be given consideration as part of future developments of TAG.  Any such scrutiny should include appropriate transport professionals and wider experts in assessing the impact of schemes, such as economists, environmentalists etc.

CIHT would be pleased to engage further with the DfT on both the development and pursuit of its new AMES. This could include a part to be played by our digital learning platform CIHT Learn that offers an important routeway for making training modules available to our 10,000+ highways and transportation professionals and to the wider sector.