This is a sore subject with me because I once worked for an EC that claimed that truck time was not to be paid. We were expected to show up to the shop, load the trucks, load the trailers, stop by the supply house if needed, the drive to the jobsite (no matter how far away) then, and only then, would we go on the clock.
That type of deal is total crap. If you abuse your guys like that, they will abuse you. Trying to pinch penny's at the expense of your men will cost you many dollars in the end.
This is not at all complicated: An employee should get paid as long as the employer is making demands of him:
Wherever a man is required to be at the beginning of the day is where his time starts. If he is required to go to the shop, his time starts at the shop. If he is only required to be at a jobsite, his time starts at the jobsite.
The same applies at the end of the day. Doesn't matter what he is driving (unless state law says otherwise): If he is required to go back to the shop, he should be paid until he gets there. If he isn't required to go anywhere once he leaves the jobsite, then his pay stops there.
-John