Driving games are good way to practice driving theory, to learn road signs and Highway Code. Of course, not all of the driving games are useful for driving theory practice. Therefore you should be critical when choosing on which games to spend your spare time. Just have quick look on visual aids appearing during game, is there any reference with signs and traffic going on the roads. If it is not, then it is no worth to spend your time and hope that you will practice driving theory while playing.