Methodology and Study Programme for an Impact Assessment of the Effects of the Jubilee Line Extension
LUCAS K and JONES P, University of Westminster, BRAY J, London Transport Planning, UK
The Jubilee Line Extension is scheduled to open in April 1999. It will run from Stratford in the east of London and join the existing line at Green Park, crossing the River Thames four times. It is the first new underground line to have been built in Lond
The Jubilee Line Extension is scheduled to open in April 1999. It will run from Stratford in the east of London and join the existing line at Green Park, crossing the River Thames four times. It is the first new underground line to have been built in London for over twenty years and will add eleven new stations to the network. Six of these new stations are in locations that have never been served by the underground network before. It is therefore, expected that the JLE will improve local accessibility considerably as well as relieving congestion on the existing network. In addition, it is expected that the line will bring a number of secondary benefits such as employment, development and increased economic activity to the areas it serves.
The JLE Impact Study Unit, established in January 1997, has been funded by London Transport Planning to co-ordinate a series of surveys and studies that will assess these impacts. It is hoped that the study will lead to a better understanding of the processes and dynamics that underpin the relationship between transport infrastructure investment and economic activity.
London Transport have identified has two key aims for the research, these are:
* To understand how the extension has affected and benefited London
* To improve future appraisal and forecasting techniques
One problem in the study of public transport impact is the relatively few opportunities to examine the effects of major investment. In Britain there have only been five major studies in thirty year, namely the Victoria Line (1963-1965), the Glasgow Rail Improvements (1979-1983), the Tyne and Wear Metro (1979-1986), the Manchester Metrolink (1990-1996), the South Yorkshire Supertram (1992-1996).
Increasingly, the methodologies developed have examined the effect of the investment, not only on transport use, but also on the economies of local areas served by new stations and/or in transport corridors served by new public transport services. This has led to a broader conceptualisation of 'impact', which includes not only first order impacts but also second order (e.g. the effect of modal shift to public transport on traffic congestion) and third order impacts (e.g. the effect of the new transport infrastructure on economic activity). In addition, there has been a recognition that people will perceive the effect of these impacts in different ways (i.e. what may be perceived as positive by one group may be seen as negative by another).
Unfortunately, many of the studies have been unable to record the longer term impacts of public transport investment either because the length of the study has been too short to allow long term monitoring and/or because the investment is too recent for these effects to have occurred.
In America, the San Francisco Bay Area Rapid Transit Scheme (BART) impact assessment has had the benefit of a twenty year follow-up study. The results of these studies suggest that the type and design of new public transport services has a significant effect on the extent to which transport benefits can be maximised, as does the efficiency and design of interchange facilities. Furthermore, BART has been seen to affect land uses only where supportive policy conditions, local community backing and an already buoyant economy were present (Cervero & Landis, 1997). The 'before' land use characteristics of areas around stations and the degree to which transportation provision is integrated with land use planning were also found to be important factors (Transport Research Board, 1996). Benefits are most evident in highly accessible, non-residential areas v~here a variety of other influences are also present. This includes a strong regional vision of the desired urban form, a political culture that supports public transport, and use of a variety of public policy tools to focus growth.
Association for European Transport