A friend of mine told me that when he was in college, there was a sign on the highway that said "sobriety check point in 1 mile". Many cars proceeded to get off at the next exit, a quarter mile up the road, where it turned out the real sobriety check point was placed. He was ok because he did not drink much but he said that many were not as lucky. From what he said, the exit they chose was not normally a very busy one because there was not much around, so it was likely that you were only exiting to avoid the stop. Creative strategy but would probably be deemed illegal these days.