Parking Patrol

I've just been to one of the local parking lots, surrounded by stores (Jewel, Osco, Target, Starbucks, Burger King, Qdoba). They have the not-uncommon parking lot patrol, a pickup truck with yellow rotating lights on the roof, slowly driving around and around and around the parking lot. I'm not sure I can imagine a worse job. Driving a highway-worthy gasoline-powered truck around a parking lot all day is an absurd waste of fuel, and I can hardly imagine a worse job than driving around a parking lot continuously. I'm always afraid of hitting someone. I'd rather do something less stressful, like demining. I also can't imagine how patrolling a parking lot in a motor vehicle works, since I'd think if the driver is being careful enough to not be at too excessive a risk of hitting someone, he's not going to be able to really look around, but patrolling on foot is, of course, unthinkable.