> Federal gas taxes don't count, because those go to the Highway Trust Fund which funds road construction, which is not an operating expense.

Doesn't the Highway Trust Fund pay for road maintenance as well?

The Highway Trust Fund pays primarily for highway capital expenditure projects. It's not just highway construction; things like replacing a bridge or widening a highway are also covered, but these are also capital expenses, not operational expenses. A portion of it goes to funding mass transit capital expenditures.

No.