Imagine if instead of roads we have some sort of low friction surface that also controls the direction of the vehicle. Some sort of metal rail. Then the vehicles could be larger, open to the public, and follow a set schedule!

And they could have additional rails that branch off the road every few miles and run directly to a set of various businesses. The system would just need a way to allow individual trucks to leave and return as deliveries are made.

I'll do you one better, use magnetic levitation so there's no friction at all. And build it in a vacuum pipe, so there's no air resistance either.

I wonder why nobody else has thought of that yet? Such a mystery.

Trolley buses work this way. Sort of a halfway house between buses and trams.