There his trucks, his employees, his customers. If he wants to track weather they shake two times or three its his business. In all honesty, tracking how long on each job sounds to me much more useful. If they are spending 50% longer on one yard then the rest, but hes charging the same amount, this allows him to at least think about a price raise for that one home.
I dont like the idea of being tracked but I know that I either am, or can be at any moment. Only real down side is that if your not paying drive time (if required by your situation) this could be used against you later.