In 2017, spending from the Highway Trust Fund exceeded revenues from taxes on highway users by $13.5 billion. A tax of 1 cent per mile on commercial trucks’ travel would have raised $2.6 billion if imposed on all such trucks and $1.6 billion if limited to those with trailers, CBO estimates. Higher rates would have yielded nearly proportionally higher revenues. Implementing such a tax would cost more than raising the existing tax on diesel fuel, however. And such a tax would raise the price of shipped goods and would cause a shift of some freight traffic from truck to rail.