Estimating changes in emissions from bus rapid transit: making best use of transport sector experience

Bus rapid transit (BRT) systems have been implemented in the last 30 years in Europe, Latin America, Oceania, United Kingdom, Asia, and North America to provide improved levels of public transport service. The associated benefits of reduced greenhouse gas emissions and energy consumption have been increasingly recognized. The clean development mechanism (CDM) provides two approved methodologies for estimating and verifying reduced greenhouse gas emissions due to modal switch induced by BRT. However, the methods do not fully account for established transport sector experience on the complexities of forecasting and measuring the direct and induced changes in travel behavior. Incorporation of relevant experience from the transport sector would lead to improved methods for ex ante estimation of changes in emissions and energy consumption. Similarly, by focusing on the key factors that influence emissions and energy consumption, verification procedures could be made more relevant and efficient. Transport sector experience also indicates limitations in the approach used to derive the baseline case in the CDM methodologies (i.e., the situation that would have been the case without the project). Current CDM methodologies also do not distinguish between vehicle drivers and passengers when considering the impact of a switch from private vehicles, and do not adequately take account of the changes in location and travel behavior that could occur. These limitations, which are equally applicable to other rapid transit improvement projects, are reviewed, and examples are given of the extent of misestimation that could occur. Consideration is also given to improved methodologies. The benefits of learnings from the transport sector are illustrated. (C) 2012 John Wiley & Sons, Ltd.