mainly because people think the law is "move over or...else." The net effect is if a cop has someone pulled over for speeding, I-81 becomes a one-lane road and backs up for miles.

I swear someone needs to call in a strafing run from an A-10 Warthog on those who stop on the interstate because they can't change lanes due to a law enforcement or service vehicle being on the shoulder. If traffic is heavy and you can't change lanes, then just slow down a little, favor the left edge of your lane, watch the stopped vehicles carefully for doors being opened or people walking around, and keep going.