A traffic cop was parked in a lay-by when a car passed him going very slowly. Concerned, he pulled the car over and discovered it contained five elderly ladies.

You do realize it is very dangerous to drive so slowly, he asked the driver.
Oh, I always observe the speed limit. Look,. there's the sign - A22.

Trying not to smile, the policeman said. 'That's not the speed limit, it's the number of the road.
Oh', said the driver, I didn't know that, thank you officer.

'By the way, madam, your passengers look a bit disturbed. One of them is shaking quite badly.

Oh' they will be O.K.' said the driver,
We've just come off the A120.

cheers Penny