Developing and Applying a Dynamic Land Use Transport Interaction Model to Identify an Outcome Based Transport Strategy and Investment Plan for Leeds
P Roberts, West Yorkshire PTE, UK; J Swanson, Steer Davies Gleave, UK
Aims of the Paper: the UK Department for Transport's Transport Innovation Fund (TIF) invited transport authorities to bid for funds to support investment packages that balance transport, economic growth and demand management. This paper will describe the work carried out in Leeds to support development of the Transport for Leeds TIF programme. It will show how the development aspirations of the city were utilised to enable a package of "objective-led" schemes to be prioritised in order to maximise GVA growth, within available funding constraints.
Context: The paper will outline the situation in Leeds now and the expected changes in future years. Like many cities, Leeds faces a future in which it expects to see significant growth in housing and jobs. This growth will bring with it rising transport crowding and congestion, and the possibility that congestion will constrain employment growth, especially in the central area, which contains roughly one quarter of the city's jobs.
Transport and the economy. The paper will describe the principles used to develop transport strategies. Transport supports economic growth by enabling employers to recruit a workforce and by providing them with access to customers and suppliers. The demand for transport and the economic value of new transport is therefore bound up with the spatial distribution of housing and employment in the city and beyond it.
The method: A land use and transport model (Steer Davies Gleave's Urban Dynamic Model, or UDM) was built to simulate the relationships between employment, households, land and transport up to 2030. In the first place it was used to demonstrate what was likely to happen if no action was taken. This produced a picture of rising congestion and crowding on the transport system as population and employment grew. It also showed how the recruitment catchment of employers in the central area would shrink in future years as the costs of commuting to the centre increased.The model is populated largely by readiliy available data and has a short (30 minute run time). It prooved to be a very useful strategic tool, to test and refine various polcies and proposals. It should be seen as an essential first step before embarking on expensive and resource intensive multi modal modelling.
Spatial analysis highlighted corridors and areas where improvements in connectivity to the city centre and other growth locations would be most effective in supporting the creation of new jobs. A transport strategy was identified to maximise the beneficial impacts of investment against the key objectives.
Potential transport interventions were developed in the light of this strategy, and tested in the UDM to assess their likely impact on a range of measures, including jobs, GVA, mode shares and carbon dioxide. Individual high performing interventions were then packaged together based on affordability levels and retested using the UDM.
Conclusions: The paper will illustrate the benefit of using a strategic land use and transport interaction model in identifying: the need for and the spatial focus of transport investment ; the importance of being able to quantify the dynamic relationships between employment and housing growth and accessibility; and the likely scale of the impact of different transport investments on employment growth, carbon emissions and accidents (as well as more conventional outputs such as trip levels, and distributions and mode shares).
It will explain how a prioritised package of investment was identified and draw conclusions on the wider lessons learned from this work that might be applicable elsewhere. In particular, it will consider what lessons have been learned that can be applied in the planning and investment context that has arisen since this work was completed, with severely reduced funding and an emphasis on supporting economic growth and employment.
Association for European Transport