Comparison of emissions from light rail transit and bus rapid transit

Bus rapid transit (BRT) is an evolving and promising transit mode that has emerged as a low-cost competitor to light rail transit (LRT) in providing medium-capacity semirapid transit. In addition, recent advances in diesel and compressed natural gas technology have caused the truism "electric rail is cleaner than diesel bus" to be revisited. A partial fuel cycle comparison of the regional or urban emissions of carbon monoxide, oxides of nitrogen, and volatile organic compounds from BRT and LRT is presented. The BRT analysis includes tailpipe exhaust emissions and fuel transportation, storage, and distribution emissions. The LRT analysis contains electric power plant emissions and line-loss-induced emissions. The analysis shows that whenever equal levels of technology are compared, LRT consistently performs better than BRT despite recent advances in the BRT mode. The analysis also shows that both modes are cleaner now than in the past.