Emerging mobility services, the surprisingly low cost of car ownership, and urban transport sustainability in the U.S. 

Abstract
As mobility services proliferate in our cities, headlines predicting the end of urban car ownership have multiplied as well. Visions of the future of urban transport focus on shared, autonomous, electric vehicles and micromobility services as critical parts of the sustainable mobility package (1, 2) – together with transit, walking, and biking. Our analysis highlights a significant economic barrier to this sustainable transport future: the low cost of owned cars. Based on a sample of more than 230,000 vehicles from the 2017 National Household Travel Survey (3), we estimate the full distribution of the per-mile cost of owned cars in the U.S. Importantly, our median estimate of $0.39 per mile is 27% lower than the federal mileage reimbursement rate in 2017. This is because ours is based on the full range of owned household vehicles – not only those that are relatively new.

We use this owned car cost distribution to illustrate how car shedding might progress if households were to shed cars that cost more per mile than they would pay for a package of alternative mobility options. We find that on a per-mile basis, nearly all owned cars in the U.S. are dramatically cheaper than emerging mobility services such as ridehail, carshare, and shared bicycles and scooters. This means that at today’s prices, these services need to be paired with a lot of walking, biking, and conventional transit usage to create a mobility package that is cost-competitive with owned cars. Sensitivity analyses suggest that this calculus can be changed, but doing so almost certainly requires increasing the cost of owned cars through parking charges, road pricing, or fuel taxes.

This is an important finding for those who hope that simply introducing emerging mobility services will induce widespread shedding of owned cars, ushering in a sustainable future for urban transport. Even in a world of technology-enhanced mobility options, traditional planning solutions for sustainable urban transport still apply: raise the cost of unsustainable options, and implement policies and investments that support sustainable alternatives.