Significant changes to policy in three core areas mean local authorities are under pressure to develop (or at least update) their transport models. In this article we outline those reasons and provide a suggested approach for making the process less daunting that it might otherwise seem…
1. Post-COVID Travel Behaviour & Guidance Changes As we have seen over the last three years, travel behaviour has changed significantly as a legacy of COVID-19 including increased remote working and flatter demand for public transport during traditional peak hours and days of the week. As recent DfT statistics show, travel demand for most modes remains below pre-pandemic levels, and importantly below the pre-pandemic projected demand level. This has major impacts on conventional transport models, which play a vital role in enabling evidence-led decision-making on infrastructure investment, future development assessment and transport decarbonisation policy implementation.
Reflecting this, the DfT’s Transport Analysis Guidance (TAG), which is the main guidance document for transport modelling, was recently updated (in May 2023) to significantly strengthen the case for producing an updated post-covid model. It states that models “… based before the beginning of the pandemic should ideally be rebased, or if this is not possible, an appropriate adjustment applied to model inputs or outputs in a proportionate way…”
2. Quantifiable Carbon Reduction (QCR) Guidance in Local Transport Plans (LTPs) Reflecting the urgency of the climate emergency, we are expecting the arrival of new DfT guidance imminently, which will include a requirement for LTPs to quantify carbon reductions from future implementation of transport plans, policies and proposals (known as ‘Quantifiable Carbon Reductions’ or QCR).
It is also highly likely that DfT funding will be allocated to Local Transport Authorities according, in part, to the decarbonisation evidenced by their LTP’s QCR. This makes getting QCR right hugely important for local transport authorities who wish to translate Government’s national decarbonisation targets to local action.
A fit-for-purpose multimodal transport model will support a more robust QCR process. For example, the transport model can be used to test different decarbonisation interventions for their impacts on reducing transport emissions such as reduction of congestion and travel demand and modal shifts to sustainable transport modes.
3. Move from Predict & Provide to Vision & Validate Application of the traditional “Predict & Provide” approach has historically tended towards the creation of transport models that are either exclusively or mostly focused on assessing road traffic, with far lower priority given to incorporating sustainable modes including active modes and public transport.
With the recent paradigm shift towards a more vision-led approach (referred to as ‘Vision and Validate’) to tackle the climate emergency, there is a need for models to shift towards a more balanced multi-modal framework. This is necessary to ensure that models can robustly assess the credibility of future transport visions and what sustainable transport infrastructure may be required to realise this.
What this means in practical terms is that transport models need to incorporate a wealth of data related to sustainable transport such as e-mobilities and shared modes alongside the ability to expand the demand segmentations to cover more detailed user classes and different time periods.
Why do Local Authorities need a Critical Friend for (re)Developing a Transport Model?
We understand that committing to a highly resource-demanding, complex and multifaceted modelling development project can be an overwhelming experience. Developing robust transport models requires a deep understanding of various domains, not only transport planning and policymaking but also specific knowledge of statistics, data analysis and traffic engineering. The interplay between these variables and the dynamic nature of transportation networks further add to the complexity. Additionally, transport models need to consider multiple scenarios, such as different time periods, population growth, land use changes, and policy interventions, making the modelling process even more intricate.
Unfortunately, this often means transport models are seen as somewhat of a “black box” by local transport authority officers, which can sometimes lead to a lack of confidence in the ability to challenge approaches being developed during the model build process, or misunderstandings in relation to future application of the model to test schemes or proposals.
We believe local authorities can benefit significantly from the input of an experienced ‘critical friend’ to help them through modelling projects of this nature.
How can City Science help?
Therefore at City Science, we now provide a Modelling Assurance Critical Friend role to unlock this ability for our clients. We are experienced both in transport model development and scheme testing (see our transport modelling case studies for details) and providing this modelling assurance critical friend role. For example, we are currently working in partnership with Herefordshire Council to help them navigate development of their 2023 Herefordshire Strategic Transport Model (HSTM).
This commission covers the following stages:
- Reviewing Existing Datasets: We help our clients to assess the extent of the divergence of travel patterns and volumes from pre-pandemic projections using the best available data and evidence, such as National Travel Survey, National Travel Attitudes Study, Transport Use During the Coronavirus Pandemic as well as the local traffic counts data, which provided evidence for the adjustments that are required for either the model data or the model itself.
- Addressing Data Gaps: We also help clients to identify any data gaps in this process and provide suggestions for cost-efficient options that can fill in the identified gaps.
- Reviewing the Existing Model: We help our clients to review how well the model was calibrated and validated following the TAG, and the model’s fitness for its application such as testing Local Plan scenarios, supporting Local Transport Strategy and business cases. The result provides a good understanding of to which extent, if at all the model can be modified to address the changes.
- Solution Scoping & Analysis: Based on the detailed review of traffic pattern changes and model fitness, we provided a list of options ranging from simple and quick adjustments for the input/output data to rebuilding the model completely. We also provide a SWOT analysis on each option, including indicative costs based on our experience with similar modelling projects.
- Model Development Procurement: Following identifying the adjustment options, we help our clients select the most long-term cost-efficient solution, and establish the internal business case to secure the funding for the modelling project. We also provide technical support during procurement, such as producing the specification and answering technical questions.
- Modelling Technical Support & Assurance: We can provide support to our clients along the whole journey of model development if required. This includes providing technical assurance of the model building process, such as bids evaluation, attending progress meetings and milestone reviews, and reviewing the key technical reports and model files.
Herefordshire’s Critical Friend
For Herefordshire, we first researched existing datasets which provided evidence for the adjustments that are required, then reviewed the robustness of the existing Hereford Transport Model, with a particular focus on its application in testing Local Plan scenarios and supporting Local Transport Strategy. As the result, we established a list of options ranging from simple and quick adjustments to rebuilding the model completely, and conducted a SWOT analysis on each option, which helped the Council officers to identify the most long-term cost-efficient solution, in this case is re-building the HSTM. We also helped the council officers to establish the internal business case/model to secure the funding for the project, then produced the model and data collection specifications, and reviewed the bid documents. Following an intense but successful procurement process for the HSTM project, City Science has been appointed by Herefordshire Council to continue to be their ‘Critical Friend’ for the ongoing HSTM development process.
Want To Learn More About Modelling Technical Advisory Services?
If you are thinking of updating your transport model please email us info@cityscience.com to see how we can support you.