Transport for London (TfL) Modelling Capability Enhancement
Tony Dichev, Transport for London, Marcel Pooke, Transport for London
Operational modelling in TfL focuses on the real-time and it’s esential to operationally manage and optimise London’s roads. The uplift to the modelling capability will enable earlier, faster and better modelling to the benefit of road network.
Road Space Management Directorate (RSMD) at Transport for London (TfL) faces an unprecedented level of network activity over the coming years. There is a need to predict, analyse, and subsequently operationally manage the vast number of large and small changes that are planned to take place across London’s road network, to balance the significant competing demands between modes and to ensure that the journey times and reliability for key modes (e.g. buses and cyclists) are protected.
RSMD at TfL has an established three-tier operational modelling capability, comprising of: tactical, 3D micro-simulation and junction optimisation models. To date, these models have varying degrees of coverage across London’s three main geographic areas (Inner, Outer, and Central), preventing a consistent approach to modelling across TfL Surface’s programme of schemes. The Modelling Capability project will enhance the geographical coverage, scope and detail of TfL’s operational models, with a focus on real-time operations, ensuring that TfL Surface can provide a more coordinated approach to the evaluation of schemes. This enhanced operational modelling capability will also enable modelling to take place earlier during the scheme design, optioneering, and assessment process. This will reduce costs to TfL and speed up the analysis stage of scheme development.
The Modelling Capability Enhancment project will deliver the following key outputs:
• Expansion and enhancements to RSMD pan-London tactical model to support major schemes implementation and TfL’s response to the Roads Task Force. This workstream will include research and software enhancements to move to a tactical modelling solution incorporating dynamic assignment (15 minute time-slices rather than whole hour aggregation, which is the current situation) and “en-route” assignment. En-route assignment will allow the operational impact of an incident to be studied in detail, by being able to see the change in behaviour of road users in the network over time and more operational decision making by give a much more realistic indication of what would happen on street. This will enable the development of short term re-assignment as a platform to full predictive modelling capability and an increased level of temporal granularity to support real-time operations;
• Accurate modelling of all modes in micro-simulation (including cyclist, bus, and pedestrian demand) to enable the impact of proposed schemes on each mode to be understood and mitigated where appropriate, and to enable schemes to be developed, that achieve optimum balance and benefits for all road users in terms of Principle Surface Outcomes. This workstream will require supporting research and development into multi-modal micro-simulation modelling (e.g. improved cycle modelling);
• All corridor models brought up to full 3D standard to aid the development of effective strategies and measures and the communication of proposed strategies/measures in a way that is accessible to all stake-holders, to gain their buy in;
• Maintain up-to-date and consistent ‘base’ models of the road network (with all models refreshed every 3 years) to accurately reflect current network operating conditions and provide an essential starting point to assess the impact of potential schemes on each mode. This workstream will also include the provision of SAN server hardware, for the storage of models in an off-site, fully supported, IM environment.
The enhanced models will fit within the established TfL modelling hierarchy. On completion of the build phase, TfL will have a pan-London suite of base models that have been developed to a consistent methodology and which will be used to service modelling requirements and deliver the c.900 signal schemes per year. This programme also provides for future maintenance and updates to the suite of models through to the end of the current business plan in 2023.
The enhancements will enable impact analysis to be undertaken of the numerous large and small changes to the TLRN and other roads that are taking place across London. This will help to ensure that the correct operational decisions are being taken, thereby facilitating the development of an overarching network operating strategy.
The modelling capability will ultimately provide enhanced operational, delivery, and management capabilities. This will allow for faster, improved, and more-informed scheme decision-making through enabling multi-modal analysis of the costs of delay, as well as the prediction of any increased operational costs for buses through the business plan period and beyond. This will put TfL in a robust position to make well informed decisions supported by a state-of-the-art operational modelling capability.
Association for European Transport