Cop pulls over a car for driving too slow..

Cop walks up to the car & sees an elderly woman behind the wheel. Cop: Excuse me mam, can you tell me why you were driving so slow on the highway? Driver: Officer, I was only going the speed limit. There was a sign back a half mile that said the it was 14mph. Cop: Mam, the speed limit is 55mph, the sign you saw was for this road, Highway 14. Driver: Oh my, that makes a lot of sense now. I apologize & I'll make sure I look closer at the signs. The cop then looks around the car& notices that all of the passengers look like they've seen a ghost. Cop: Is everyone alright? Driver: Oh yes. They'll be fine. Theyalways have that look on their face after I drive on highway 151.