Earlier quoted context omitted.
> You could get the same benefit just by adding the class to the high school curriculum. This doesn't contribute to the upkeep of roads in the same manner as a yearly tax on those that use them. So no, not the same benefit at all.
You're thinking of car tax and fuel tax. But also, the value of roads scales poorly with any of these things. The ability to have a package delivered to your front door is valuable regardless of whether or not you even have a car, and the value of it depends on what's in it rather than how much the truck cost. The most sensible way to fund any kind of basic infrastructure is from general revenues.
But yes, truck used to haul building materials for a building site is the vehicle fulfilling its purpose and any replacement for that purpose being suboptimal.
Truck bought to haul 2 bags of groceries is not. Tax the second one.