The transit industry must meet the challenges of cost-effective operations while meeting clean air emissions requirements. Over the last 15 years, various transit systems have used an assortment of alternative fuels, often while the technologies were under development, with varying degrees of success. Too often, careful technical analysis of alternative technologies has happened later than desired.

The next generation of new bus-propulsion technology is arriving. Hybrid-electric buses are being promoted as being more cost effective (both capital and operating); more reliable; and more energy efficient than conventional diesel and superior to alternative fuel options (e.g., compressed natural gas, liquefied natural gas, propane). This propulsion technology needs to be independently analyzed so that transit agencies considering hybrid-electric buses can make well-informed decisions.

Some transit agencies are investing substantial amounts of federal and state capital resources to buy buses equipped with hybrid-electric propulsion systems. Research is needed to leverage this substantial capital investment by providing a sound, independent, technical evaluation of the impacts of this bus-propulsion technology in actual transit service. The results will be analyzed and published so that the entire transit industry can learn from these experiences.

The objective of this research is to develop guidelines to assist transit managers in the assessment, selection, and implementation of hybrid-electric technology options for transit buses. The guidelines will be based, in part, on a sound, engineering-based, independent technical evaluation of the costs, performance, and reliability of hybrid-electric transit bus technology in actual service.

This project will be of interest to transit managers, policymakers, operations and maintenance professionals, and others considering the deployment of, or conversion to, hybrid-electric transit buses. The deliverables are intended for individuals who, although knowledgeable about the transit industry, may not be familiar with hybrid-electric technology implementation issues.

Status:   The final report has been completed and published as TCRP Report 132 and CRP-CD-71.