A Highway Lesson

When a policeman sees a car driving along the highway at only 22 miles per hour, he thinks, "Driving this slowly is as dangerous as speeding!" and stops the car.
Five elderly ladies are inside, wide-eyed and white as ghosts. The driver asks "Officer, what have I done wrong? I was doing 22, exactly the speed limit!"
Smiling, the officer explains that "22" is the name of the route, not the speed limit.
"But before you go on," says the policeman, "is everyone in this car OK? The other ladies look like they're really afraid - and they haven't said a word."
"Oh, they'll be all right in a minute, officer. We just got off Route 119."