If you are a driver at some point in your career you will have to cover somebody else's route. Besides the "Where am I going and how do I get there?" problem the biggest problem you can run into is the normal driver does things the wrong way and people on that route expect you to do the same things they did. By "wrong way" I mean things like driver releasing packages for businesses, forging signatures for businesses, and driver releasing packages at an apartment out in the open where anybody can take them (it can only be done if they sign up for my choice). I've heard and experienced situations where the driver gets yelled at by the customer for doing things the right way unlike their normal driver. In one case the cover guy who got yelled at by a customer for doing things the right way complained to management who was all too happy to ream the normal driver when he got back. Long story short get a [email protected] signature when you deliver to businesses or apartments.