Can Bus really be the new Tram?

BRT appears to be less expensive to build and operate than tram systems but can it really approach the performance level of a tram system and what is the environmental performance of comparable systems? This paper reports systematic research on these issues, particularly relating to where an urban transit system seeks to attract discretionary car users. A model has been developed to compare the implementation, operational costs and environmental impacts of a comparable tram and high quality guided BRT system. This models a UK situation, but draws upon information from elsewhere in Europe and North America. The design of the BRT system delivers equivalent performance to trams in capacity and passenger experience. This ‘equivalence’ model shows that the capital costs of the high-spec BRT system are two-thirds those of tram. This is less of a cost saving than is often claimed, suggesting that, in practice, BRT is built to a lower specification that tram systems. Operational costs do not significantly differ. Using hybrid-engine BRT vehicles, CO2 emissions are similar, BRT has lower PM10 emissions, but NOx from BRT remains higher than for trams. Although the cost differences for equivalent systems are less than is often claimed, there are substantial benefits in the flexible development of BRT, with it less vulnerable to variations from forecast ridership numbers, and development can be split into fundable stages, growing the business case for incremental upgrading. High-spec BRT can to be the new tram, but the ‘value for money’ case for BRT should not be at the expense of quality and transport planning impact. 1. The demise of Light Rail and emergence of Bus Rapid Transit The development of new light rail systems in the U.K. has all but ceased after the construction of a handful of large city schemes. Only Edinburgh is now seeing the construction of a new tram system, and this is beset with serious programme, project overrun and overspend issues (Foster, 2011). There are some extension projects underway to existing tram systems, including Nottingham (NET), Birmingham (Midland Metro) and Manchester (Metrolink), but these are exploiting the existing investment in their initial systems. A number of schemes have failed in the planning stages, including Liverpool, Leeds and South Hampshire. In the wake of this, a UK National Audit Office report (NAO, 2004) concluded the failings of light rail to be: