A state cop sees a car driving down the highway, going extremely slowly for a four-lane highway.

So this cop pulls over this car, which is being driven by an extremely old nun, with two elderly nun companions in the back seat.

The cop asks her "Ma'am, do you know what the speed limit is here?"

She says "Yes, officer, it's 21," and points to a sign out the window.

The cop looks, and says "Ma'am, that's the ROUTE marker. This is Route 21."

The nun looks up, comprehension dawning in her eyes. "Ah!" she says. "That explains the screaming!"

The cop says "What? What screaming?"

The elderly nun looks back over her shoulder and says "We just came off Route 119."