City Buses with Alternative Power Trains under Realistic Driving Conditions

City buses with hybrid and battery electric power trains as well as conventional reference vehicles have been examined using a standardized methodology, mainly focusing on exhaust and noise emissions, overall energy efficiency and operational availability. A combination of realistic test drives on bus lanes, test track runs, long term data acquisition and simulation has been utilized to conduct a complete assessment of the technology. First results indicate an improvement over conventional city buses in every technical area