SF BART stations have restrooms with keys that have expiration dates.

Photo of a label above the lock on a restroom. It says:&10;&10;Men's & Women's Keys:&10;M22&10;M23&10;M24&10;M25&10;M26&10;M27&10;M28&10;W22&10;W23&10;W24&10;W25&10;W26&10;W27&10;W28&10;Numeral is year key expires.