A tale of two perspectives: the mileage-based user fee conundrum

The limitations of the current transportation funding system based on federal and state gas taxes have resulted in steep shortfalls in the Highway Trust Fund in the U.S., especially given the growing adoption of high fuel-efficient gasoline vehicles and electric vehicles. While the notion of mileage-based user fees (MBUF) has received attention as an alternative to the current gas tax, public support for MBUF is still low. In this study, we unravel the potential reasons for such low public support by examining the perceived fairness of the MBUF system through the conceptualization of fairness from two perspectives: the perspective that MBUF is fair because everyone pays equally for using the infrastructure, and the perspective that MBUF is less fair because those who adopt cleaner vehicles are not rewarded. Using a bivariate ordered model with attitudinal variables, and employing data from the first wave of the Transportation Heartbeat of America (THA) Survey conducted from October 2024 through January 2025, the effects of socio-economic, demographic, and attitudinal factors on each of the two perspectives of MBUF fairness are examined. The findings suggest substantial heterogeneity in fairness perceptions based on these factors, as well as based on the specific perspective of fairness considered, underscoring the importance of positioning MBUF-based policies with care and sensitivity to different groups of individuals to garner broad support.