Life-Cycle Assessment for Transportation Decision Making

Abstract

Life-Cycle Assessment is a framework for evaluating products, processes, services, activities, and the complex systems in which they reside, from cradle-to-grave. When Life-Cycle Assessment is applied to transportation infrastructure, the analysis can evaluate the vehicle manufacturing, fuel production, and infrastructure construction phases not accounted for in a typical environmental analysis. Because a Life-Cycle Assessment can produce additional information about an alternative or set of alternatives, some transportation agencies are interested in pursuing such an analysis in their transportation decision-making. This paper provides guidance for agencies seeking to conduct a Life-Cycle Assessment of various transportation infrastructure options to aid in decision-making. The authors organize frameworks and methods by existing processes and decision points in order to ease the integration of Life-Cycle Assessment methods into the current transit planning and operations environment. Guidance to transit agencies wishing to perform Life-Cycle Assessment of new capital projects is presented, with consideration of policy and data trade-offs that an agency will likely encounter when conducting a Life-Cycle Assessment. Possible energy and emissions implications for land use are discussed. The authors found that many agencies lack data to perform a precise Life-Cycle Assessment at any one stage of the capital planning and delivery process, and that existing planning processes preclude detailed assessment and substantive decision-making in the same stage. The paper concludes with recommendations for California and the U.S. Federal Transit Administration to facilitate local Life-Cycle Assessment, such as producing information on life-cycle energy and emissions impacts for transit vehicles and projects.