Western Australia is similar - three times the land area of Texas and large areas of "private" roads - Minesites, Wheatbelt (both have their own private rail systems in addition to road ways and open fields / oterwise off road).

There are fleets of vehicles I'm aware of that rarely, if ever, hit tax payer funded public roads or rail.

These fleets include graders, dozers, rollers, et al for private road maintenance.

These are real, your skepticism is understandable but not applicable.

In parallel with private vehicles on private roads there are also public roads upon which school buses travel (assuming kids don't just off-road it to school on a motorcycle or, still today, a horse).