I'm a UPS driver, and there is no certain amount of time a vehicle can be parked. In NYC the trucks are parked in the same spot all day long. UPS does know everything we do during the day. They know when the truck is idling, speed, backing, distance travelled, speed travelled, seatbelt on, door open, when I'm using hitting keys in my computer. If people think they are micromanaged at their jobs, then they have no idea how much worse it could be. In most cases the driver decides if the package is safe to be left. The Fed Ex driver in my area leaves packages at most of the businesses without a signature. UPS doesn't allow packaged left at businesses without one. I deliver in northwest Milwaukee, and I won't leave a package at an apartment unless the shipper designated it to be left unsigned.