The Passive Laser Restraint System is a harmless laser beam that helped protect Michael Knight and any passengers from the shock of sudden impacts and hard stopping, especially after Super Pursuit Mode. It is speculated that this is a primitive form of an inertial damping device.
Knight of the Drones
Although the Laser Restraint System was some sort of precursor to inertial dampening fields, it was never described as such. The Passive Laser Restraint System was introduced at the beginning of Season 3 to promote safe driving by reminding kids to wear their seat belts. In "Knight of the Phoenix" and "The Final Verdict" Michael used restraint harnesses to keep him and his passengers from flying all over the place.