Cop pulls over a carload of nuns.

Cop: "Sister, this is a 65 MPH highway. Why are you going so slow?"
Sister: "Sir, I saw a lot of signs that said 22, not 65."
Cop: "Oh sister, that's not the speed limit. That's the name of the highway
      you're on!"
Sister: "Oh silly me! Thanks for letting me know. I'll be more careful."

At this point the cop looks in the backseat where the other nuns are shaking
and trembling.

Cop: "Excuse me, Sister. What's wrong with your friends back there? They're
      shaking something terrible."
Sister: "Oh, we just got off of highway 119."