Estimating the impact on fuel tax revenues from a changing light vehicle fleet with increased advanced internal combustion engine vehicles and electric vehicles

Advanced fuel economies in both traditional internal combustion engine vehicles (ICEs) and electric vehicles (EVs) have a strong influence on transportation revenue by reducing fuel consumption per vehicle and ultimately drawing down the amount of fuel tax revenue received. It is expected that more ICE vehicle with advanced fuel economies and electric vehicles, especially gasoline hybrid electric vehicles, will enter the roadway in coming years, and fuel tax revenues and the Highway Trust Fund will increasingly become more affected. This study estimates the impact that increased sales of advanced ICEs and EVs will have on future fuel tax revenues by drawing on industry estimates of future EV and ICE market shares and anticipates future fleet mix and fuel economy for both vehicle technologies. An estimation process overview is provided and assumptions are described.

Fuel tax revenue amounts that would be expected from future light vehicle fleets with increased shares of EVs are compared to equally sized fleets comprised of all ICEs, and future fleet mixes are estimated. Results show that as more electric vehicles enter the light vehicle fleet, greater revenue losses are expected, and total losses from years 2011 through 2050 depend on fleet composition and fuel economy of both vehicle types. Finally, it is found that the amount of fuel taxes paid by ICE drivers each year remain greater than fuel taxes paid by EV drivers even with advances in the average ICE vehicle fuel economy.