Hi masters of game programming

I´m doing a moto racing game. I already did the users movements (controls like acceleration, curves (_rotation), reverse speed etc), but I would like to know a way to do the adversary movements (A.I), capable to win the race.
The game is top viewed, you can see all the track with the motocycles on it.
Any one?
Look at the attached files, theres a swf of a racing car, its just like that but with motocycles. Look and then tell me how to do it.

Many Thanks