Thats a good question. Now we all know the problem out there with truck parking. Solo drivers who choose to wait till after 1700 to park, may be out of luck depending on the part of the country they are in. I personally have seen more than one accident where a vehicle has ran into the back of a truck parked on the off ramp. I even pulled over to check on a co-worker that was on the shoulder of the interstate. I knocked on his door, wakeing him up to find out he was just tired and needed a nap. In a pinch I have been known to park on the on ramp or even 3/4 of the way up an off ramp. But never never the begining of the off ramp and never the shoulder of the interstate. As profesional drivers we should plan our driving day so we could reduce the potential of not getting a parking space. I know this is impossible to do alot of the time but that is all we can do. Peace.