Abstract:The Sustainable Transport Energy Program (STEP) is an initiative of the Government of Western Australia, exploring hydrogen fuel cell technology as an alternative to the existing diesel and natural gas public transit infrastructure. This project includes three buses manufactured by DaimlerChrysler with Ballard fuel cell engines, operating in regular service alongside the existing natural gas and diesel bus fleets.The Life Cycle Assessment (LCA) of the Perth fuel cell bus trial determines the overall environmental footprint and energy demand by studying all phases of the complete 2 transportation system, including the hydrogen infrastructure, bus manufacturing, operation, and end-of-life disposal. LCA's of the existing diesel and natural gas transportation systems are developed in parallel.The findings show that the Perth fuel cell bus trial is competitive with the diesel and natural gas bus systems in terms of global warming potential, and eutrophication. Emissions that contribute to acidification and photochemical ozone are greater for the fuel cell buses.Scenario analysis quantifies the improvements that can be expected in future generations of fuel cell vehicles, and found a reduction of greater than 50% is achievable in the greenhouse gas, photochemical ozone creation, and primary energy demand impact categories.