Introduction

In this section the evidence of the contribution of new light rail schemes to achieving objectives and solving problems will be assessed. The evidence is not substantial, partly, at least, because of the lack of systematic before-and-after studies to assess the impact of such systems.

Contribution to economic efficiency

It is clear that many people now use the various light rail systems that have been developed in recent years. By adding a new mode of transport, the overall disutility of travel has decreased, making travel more efficient for some people. However, the number of passengers is small compared with the number of bus users in some areas, such as Greater Manchester (but quite large compared with heavy rail), so the addition to the supply of transport is fairly small, which means that the potential to increase economic efficiency is rather limited.
Whilst there are new users of the systems, and some evidence of transfer from the car to light rail, for example in Manchester, Sheffield and Lausanne, this does not seem to manifest itself as a net reduction in road traffic. Although, in Manchester there was some evidence of a reduction in car use to the city centre.

All the systems cost large amounts of money to construct. Most systems require operating subsidy, which means that resources will be consumed on a continuous basis. Notable exceptions to this are the systems in Manchester and Sheffield which are now both operated by the private sector with no subsidy. Of course, the capital costs have been paid for by the public sector.

The studies of the impacts of new light rail schemes on house prices show very little evidence of significant impacts, but the studies have been conducted very soon after the systems opened and so the effects may not have shown up at the time.
Overall, there is little evidence that light rail systems contribute to economic efficiency.

Contribution to liveable cities and neighbourhoods

Whilst it seems intuitively obvious that building a modern, efficient, not polluting (at source) public transport system should help to make cities and neighbourhoods more liveable, the direct evidence of their doing so is very sparse.

Contribution to protection of the environment

Just as it seems obvious that light rail schemes should make cities and neighbourhoods more liveable, they ought to help protect the environment by providing an attractive alternative to car users who will then use their cars less, thereby producing less pollution. Because of the lack of evidence of reductions in car use, there is little evidence of increases in environmental protection.

In fact there have been concerns about environmental damage by new systems, with noise being seen as an issue in Lausanne and Vancouver and visual intrusion in Manchester and Sheffield. Such concerns tend to disappear once the system is running and has become part of the urban landscape.

One way environmental damage can be restricted is by specifying acceptable limits in a contract if the system is being put out to tender to the private sector to operate (and possibly design, build and maintain). Any companies bidding for the contract have to incorporate the cost of meeting such limits in their tender prices. The limits can be enforced in the courts if necessary. Of course such a method of limiting environmental damage is not restricted to light rail systems, but it is much easier to impose such requirements with a new system than it is to introduce them into an existing contractual arrangement.

Contribution to equity and social inclusion

Light rail is a form of public transport, and when public transport is looked at as a whole, many users tend to have below-average incomes. However, if the objective of a light rail scheme is to attract motorists out of their cars, then it has to serve areas of high car ownership and to offer a high quality journey which might imply high fares.

In Manchester and Sheffield there was some evidence of use by the elderly and other off-peak users, but there is little direct evidence of light rail schemes helping to increase social inclusion in terms of providing travel opportunities for those suffering from social deprivation. The systems in Croydon, Tyne and Wear and the West Midlands have all been designed to provide access from areas of high unemployment to areas with vacant jobs, but there is no evidence on how successful they have been. There is the example of Los Angeles (Wachs, 1993) where funding was transferred from bus services in the inner city serving low-income households to subsidise the light rail system serving high-income households because it could not cover its operating costs, thereby leading to a loss of equity.

Many light rail systems run from outer prosperous areas to the city centre, passing through inner urban areas which house low-income households. In some cases, for example, Vancouver, San Jose and Rouen, the systems were used as catalysts to help regeneration which can lead to jobs and investment in infrastructure in these areas. Generally this involves using complementary policies to help in the regeneration process, and it may be these policies which actually help reduce social exclusion by offering jobs and so providing income, but the light rail scheme is required as the catalyst.

In summary, light rail schemes can be used to help reduce social exclusion, but this may well be indirectly through increasing investment in deprived areas leading to economic regeneration rather than directly as a form of public transport.

Contribution to safety

Light rail is very safe compared to the car and so its introduction into an area should increase the overall safety of the area as people transfer from the less safe mode. However, no direct evidence of this has been found in the literature.

Contribution to economic growth

The stimulation of development is a key objective for the building of many light rail systems. A new light rail system will not, on its own, induce development, but it can form part of a package to facilitate development. It plays several roles in the process: it provides a modern, efficient way for residents to reach jobs outside the area, it provides access into the area for workers, shoppers and those on leisure trips, it demonstrates a commitment to the area by various levels of government, it provides a useful theme for marketing the area, and so on. In order to implement these concepts there needs to be investment in housing, jobs, shops and leisure facilities. Most of this will be by the private sector which will see the commitment made by the public sector to the light rail system and will recognise that the system will convey workers and customers in a suitably high technology style, that a bus simply would not do. In order to start the development process off, incentives of various sorts may have to be offered, such as tax reductions or reductions in planning restrictions. These issues of complementary policies are discussed in the next section, but it is important to note here that light rail has a role to play in the urban development process along with other policy instruments.

In terms of the systems examined here, neither Manchester Metrolink nor Sheffield Supertram seem to have had much impact in terms of development. There are at least two reasons why this may be the case: from about 1989 to about 1994, Britain was in economic recession, so there would not be much happening in the form of development with or without light rail, and secondly, the survey work was carried out within a few months of the opening of the system, and it could take several years for definite evidence of development induced by the light rail system to show.

Evidence of development impacts were found for the new systems in St Louis, San Diego, San Jose, Portland, Calgary, Vancouver, Rouen and Tyne and Wear. In these cases complementary policies were used and there have been at least some years since they opened when their national economies have not been in recession.
Some other systems, those in Baltimore, Los Angeles and Sacramento, have not induced development to any significant degree, and are regarded as generally not very successful (Babalik, 2000, Mackett and Babalik, 2001a).

It can be seen that light rail systems can be used with complementary policies to stimulate development in particular areas. In some cases this may be simply a matter of shifting development from one area to another, and therefore not necessarily adding to the overall level of economic development in the city. In other cases, it may be making the city served by the light rail system more attractive than other cities without such a system, and so adding to economic growth locally, but not at a regional or national scale. That may not matter if it is desired to stimulate development in a particular area, for example to help 'kick-start' a major regeneration process.