One night at a local pub frequented by a notorious bunch of hot-rod drivers, the local cops staked out the place waiting for drunk drivers.

As the cops waited, eventually Tommy stumbled out of the bar, fumbled for his keys, tried them in three different cars until he finally found his, got inside and rested his head on the steering wheel. The cops knew they had a drunk driver, so now all they had to do was wait for him to start his engine and pull out of the car park.

A few hours passed by and most of the other drivers had left by then, when Tommy abruptly lifted his head, cranked the car up and drove out like a bat out of hell. The cops followed him and stopped him promptly.

They administered a breath test and it read 0.00. Confused, the cop asked Tommy what the hell was going on.

Tommy looked at him innocently and said, "Well, tonight I was the designated decoy."