Network-Level Life-Cycle Energy Consumption and Greenhouse Gas from CAPM Treatments

This report describes a life-cycle assessment (LCA) approach developed to evaluate the energy consumption and greenhouse gas (GHG) reductions from the use of pavement maintenance treatments that improve smoothness on the California State Highway Network, as well as the cost-effectiveness of this approach. This analysis developed optimal roughness values to trigger maintenance and rehabilitation treatments to minimize life-cycle GHG emissions (measured in equivalent CO2 emissions [CO2-e]) as a function of the traffic volume of each pavement segment in the network. A set of pavement characteristics were used to describe each segment of the network and to evaluate the impact of pavement-induced rolling resistance under different pavement and traffic conditions. With the optimal trigger values, annualized reductions on the California State Highway Network over a ten-year analysis period were calculated to be 0.82, 0.57, and 1.38 million metric tons compared with results using historical trigger values, recently implemented values, and no strategic intervention (reactive maintenance), respectively. Abatement costs calculated using $/metric-ton CO2-e for agency costs alone were higher than those reported for other transportation sector abatement measures. However, consideration of the user cost benefits associated with pavement smoothness, such as increased vehicle life and lower maintenance, substantially improves the abatement cost. Also considered in the report are the effects of delaying construction after optimal triggering.