Assessing Urban Transport Policy Impacts Using a Highly Aggregate Strategic Model
RAttA N, Transport Research Laboratory, UK
There is increasing global consensus on the need for sustainable development and the necessity of encouraging a more environmentally friendly use of resources. The transport sector is a major contributor to greenhouse gas emission. The primary policy docu
There is increasing global consensus on the need for sustainable development and the necessity of encouraging a more environmentally friendly use of resources. The transport sector is a major contributor to greenhouse gas emission. The primary policy document in Britain giving guidance to local authorities when bidding for funding for transport package bids is the PPG13 (DOE/DOT, 1994). This document stresses the need for encouraging modal shift away from the car to more energy and environmentally efficient modes. At the same time, government guidelines highlight the requirement to retain the vitality and viability of city centres (DOE, 1994).
British local authorities are encouraged to progress towards integrated transport strategies for their urban areas. Transport modelling plays an important role in the demonstration of the relative merits of proposed schemes in achieving PPGI3 objectives. Ideally a large strategic transport model might be used. Such a model requires large amounts of high quality travel survey data. This can be expensive to collect and may not always be available.
This paper discusses some results of the application of a highly aggregate strategic model, the Transport Research Laboratory's two-zone Single Link Model (SLM). This model is useful for the rapid assessment ofa.wide range policy options in a discrete urban area using only very limited travel and ancillary data. This paper focuses on the recent application of the SLM to the Manchester urban area, conducted by TRL on behalf of the Greater Manchester Transportation Unit (GMTU). Further details of the SLM can be found in Dasgupta et al. (1994) together with a discussion of its application to assess the impact of transport policies in the five cities of Leeds, Bristol, Sheffield, Derby and Reading. The aim of both studies was to model the potential qualitative impacts of six policy tests on various key indicators such as trip numbers, mode choice and trip redistribution.
Association for European Transport