The report focuses on alternative drivetrain technologies and fuels that offer carbon reduction from city buses, although technologies relevant to taxis are also discussed.

The analysis focuses on the likely performance of short-medium term solutions (< 10 years) and suggests some demand side measures and practises which can be implemented to assist in the transition to cleaner public transport fleets. The study draws on technology information from industry technology roadmaps, interviews with technology providers and industry experts. Future demand for public transport vehicles and current procurement practises are established from the PPIA network cities.