It seems to me you are screwing the guy over doing this. If someone pulled this on me I would be pissed about it.Suppose that the job is an hour and a half from the shop; what's more, it's on a route that runs right by the tech's house? The "standard" way requires that you burn 3 hours per day in travel, and the tech gets paid for it and there's 5 hours of productive time possible. Let him keep the truck, make sure he has what he needs, tell him he has to be on the job site by 0700 and the travel time in is unpaid. Let him quit at 1430 ( with 15 minutes to clean up and 15 for paperwork) and he's home by 1600, just like he was punching in back in at the office. In this case, you have 7 hours of productive work time possible. It seems like a doable compromise.
It seems over elaborate to me as well.
Just be fair with the guy and pay him for the time he is spending on your business. If that makes the job too expensive, turn it down.