The development, design and evaluation of sustainable local transport networks

Abstract

This paper is about the relationship between urban areas and transport, particularly the design and evaluation of sustainable local transport networks. It is presented in the context of the changes in thinking associated with new ideas for traffic engineering in the urban environment, to accommodate the complex mix of activities arising on highway networks, which are now taken into account by decision-makers; ways by which urban planning can help to bring about greater use of sustainable transport modes; the growing influence of architects and urban designers on street pattern and road layout in modern British housing schemes. After reviewing the history of urban form and the theories that have guided various trends in design, the paper comments on developments and identifies the shortcomings of lower densities and inflexible networks, particularly with regard to reinforcing the reliance on a single, unsustainable transport mode. More recent trends in the design of urban areas in Britain are noted: more continuous street patterns; a less rigid application of the simple road hierarchy; a more equal treatment of the different transport modes. As design ideas develop the need to appraise transport networks arises in parallel. The final section identifies a range of techniques for analysing networks. The paper concludes by noting that sustainable travel systems can be encouraged by increasing urban densities and ensuring that street networks are designed to favour the more environmentally sound modes. To achieve this, there needs to be an emphasis on the measurement of the performance of street networks. Quantitative appraisal techniques will become an essential part of urban planning in the future.