Like most drivers over here I get paid by the mile (plus drop, pick up, switch and unloading pay).
When I am in the Albany area after a delivery my dispatcher will sometimes ask me if I have time to move some trailers from ‘Price Chopper’ to ‘DUI’, these places are only half a mile apart and are sparated by a railway bridge. The dispatcher will say I will swipe a time card for you, thus putting me on hourly pay, however ! I have sussed out that these two places are in different zip codes as the rails form the boundry and I get paid 12 miles each way which works out at $10 round trip plus $5 to switch trailers, each trip takes 10 minutes so if I stay on miles I earn around $90 an hour when I am doing it. 
By the way, I have done this a few times and they pay without question.