University of California Transportation Center

The passenger transportation modes of rail and air are critical systems relied upon for business and leisure. When considering their environmental effects, most studies and policy focus on the fuel use of the vehicles, and ignore the energy and other resource inputs and environmental outputs from the life cycles of other components. Vehicle manufacturing and maintenance, infrastructure construction and operation, and fuel production are rarely included in environmental factors for transportation systems.

The goal of this project is to develop a comprehensive life-cycle assessment model to quantify the energy inputs and emissions from rail and air transportation in the U.S. associated with the life-cycle components (raw materials extraction, manufacturing, construction, operation, maintenance) of the vehicles, infrastructures, and fuels involved in these systems. Energy inputs are quantified as well as greenhouse gas and criteria air pollutant outputs. Inventory results are normalized to effects per passenger-mile traveled.

Results show that energy and greenhouse gas emissions increase by as much as 2.1 times for heavy rail, 1.4 times for high speed rail, and 1.3 times for air when life-cycle components are included. Criteria air pollutant emissions increase between 1.1-29 times for heavy rail, 1.2-1.4 times for high speed rail, and 1.5-9 times for air.