University of California Pavement Research Center

California state government has established a series of mandated targets for reducing the greenhouse gas (GHG) emissions that contribute to climate change. With a multiplicity of emissions sources and economic sectors, it is clear that no single change the state can make will enable it to achieve the ambitious goals set by executive orders and legislation. Instead, many actors within the state’s economy—including state agencies such as the California Department of Transportation (Caltrans)—must make multiple changes to their own internal operations. The focus of this study and technical memorandum is to examine several strategic options that Caltrans could adopt to lower its GHG emissions in operating the California (CA) state highway network and other transportation assets so it can help meet the state’s GHG reduction goals. Although many GHG reduction strategies appear to be attractive, simple, and effective, most also have limitations, trade-offs, and unintended consequences that cannot be identified without a preliminary identification and examination of the full system they operate in and their full life cycle. To achieve the most rapid and cost-effective changes possible, the costs, times to implement, and difficulty of implementation should also be considered when the alternative strategies are being prioritized. This project first developed an emissions reduction “supply curve” framework by using life cycle assessment (LCA) to evaluate full-system life cycle environmental impacts and life cycle cost analysis (LCCA) to prioritize the alternative GHG-reduction strategies based on benefit and cost. This framework was then applied to an example set of strategies and cases for Caltrans operations. This technical memorandum presents the results of the supply curve framework’s development and its application to six strategies for changing several Caltrans operations identified by the research team. The six strategies were: (1) pavement roughness and maintenance prioritization, (2) energy harvesting using piezoelectric technology, (3) automation of bridge tolling systems, (4) increased use of reclaimed asphalt pavement, (5) alternative fuel technologies for the Caltrans vehicle fleet, and (6) solar and wind energy production on state right-of-ways. A summary of the methodology and the resulting supply curve that includes all the strategies considered and ranked is published in a separate white paper. This technical memorandum provides the details, assumptions, calculation methods, and results of the development of the GHG reduction supply curve for each strategy. Although this current study’s scope is limited to development of a supply curve for GHG emissions only, there are plans to expand the study’s scope to include other environmental impacts and to develop supply curves for them as well.