As the variety and sales of electric vehicles have grown, the average capacity of batteries in U.S. EVs have also increased. If the current trend continues, by 2020 the average vehicle sold would have three times the battery capacity of the comparable EV a decade earlier. Larger lithium ion battery systems could increase the average weight of vehicles and axle loads.
Increasing vehicle weights is a concern for the maintenance and design of pavement and road infrastructure. There are three primary factors that contribute to damage in pavements: traffic loads, climate, and time. Climate and precipitation weaken the structure of pavements, especially without well-designed drainage systems, while changes in temperature cause thermal cracking in asphalt pavements, as well as warping in concrete pavements. Over time, asphalt becomes brittle and stiff due to oxidation and evaporation of volatile components. The combined effects contribute to the exponential relationship between axle loads and pavement damage. Pavement thickness is primarily dependent on maximum axle loads (e.g., trucks volumes), and trucks are disproportionately responsible for traffic load damage. But the total volume of materials used for road construction, maintenance, and rehabilitation is dependent on the volume of lanes, which is primarily dependent on level of service for passenger vehicles. Even more critically, shifting or generally increasing the distribution of traffic axle weights can have implications for bridge design and survival.
This study will explore the impacts of vehicle electrification policies on traffic loads in California. The white paper will provide estimates of how increased vehicle electrification could impact axle weights, average traffic loads, and pavement damages. The research will support the state’s EV policies and continued investments in roadway construction and maintenance.