At the Main menu, highlight the (trial by trucking) option and press the Y button and the cheat menu will appear.

BIKERS - Adds lots of bikers
BRIDGE - Opens all bridges
CASH - Gives you 115,000
COPS - Adds lots of cops
GALLERY - Unlocks all of the gallery images
MISSIONS - Unlocks all mission within the game
NOCOPS - Removes all of the police
NODAMAGE - Makes you invincible
PJ - Pay off next juror