I'm wondering if some sort of kiosk mode would work. I have zero experience with this myself, but I believe they can be used to eliminate access to everything except what the users should have. In other words, the drivers would see nothing but what you want them to see/use.
I vaguely remember a 'family tracking' feature I set up on one of my early Android phones, just for the hell of it. It had to be through Google...a quick search yielded
this support page about it. The app is called
Family Link, and is intended for parents to control what their children can do--and shows where they are. I don't know about any potential legalities using it for adults. The point really is, though, that this is doable. Maybe not with this app, but doable.