It grows when those services disappear.
US households on average drove 22,311 miles last year, down 8 percent from all-time highs.
Fuel-efficiency average doesn't budge from 2015 or 2104 level, as more trucks sales offset higher plug-in vehicle demand.
It's the lowest figure since July 2013.
UMTRI's paper weighs the merits of BEVs and FCEVs, and compares them to gasoline-powered cars.
US average new-car fuel economy remains unchanged at 25.4 mpg in July, UMTRI says.
A study by the University of Michigan Transportation Research Institute finds diesels are much more economical to own over three to five years than gas models.
The University of Michigan Transportation Research Institute calculates the average MPG of new cars sold in the US, and finds that June was worse than May.
A newly released study from the University of Michigan Transportation Research Institute finds that around 10 percent of people riding in an autonomous car might experience motion sickness, if they aren't paying attention to the road.