Bill and Joe are two long-distance truck-drivers. One day they are driving their 44-tonne truck on a small road in Europe, when they come to a bridge.
"Oh look! " says Bill. "Look at the sign ! It says Maximum weight 20 Tonnes."
"Oh !" says Joe. Then he says; "Wait a minute, I'll get out and have a look!"
A minute later Joe comes back to the truck, and says ; "OK Bill, no problem! I've had a look. Let's go ! There are no police on the other side. "