Department for Transport: National Transport Model v5 2024 Rebase

Descriptions

The National Transport Model version 5 (NTMv5) is a large transport model, developed using classic transport modelling principles but with a number of adaptations to enable it to be sufficiently informative with shorter run times. Some parts of the model use a "masking" system with a representative subset of zone-to-zone movements, to reduce computation times. The Department for Transport is considering a `rebase' of the system. There are three important elements to this work. First, and most important, the requirement is to update the highway assignment component of NTMv5 to reflect the situation post-covid19. This is needed for strategic forecasting purposes. In practice, this means using data from 2022 and 2023, a shorter period than the original data used to estimate NTMv5. The challenge with this work will be to exercise judgement about where compromises are needed to meet the tight timescales for this project, whilst still providing sufficient quality for strategic forecasting. This work may also provide some opportunity (albeit within limited timescales) for an innovative approach to meet this challenge. Secondly, we intend to switch from using National Highways traffic counts to the Department's data (potentially including traffic by region and road type as well as counts) for this update. This is because for strategic forecasting purposes, the Department requires the modelled traffic to match its own understanding of traffic in the model base year. Finally, the Department would like to have the capability to carry out similar updates in-house in future. Therefore, we would anticipate allowing some time after the model updates are complete for documentation, handover, and potentially training to the Department in the methods used for this update.