I WAS AT A FULL STOP, BEHIND A LINE OF CARS, AT A RED LIGHT, ON A CITY STREET. A JEEP LIBERTY SUV REAR-ENDED ME AT APPROXIMATELY 30 MPH, PUSHING ME INTO THE CAR IN FRONT OF ME, AND TOTALING MY VEHICLE. MY SHOULDER BELT DID NOT LOCK IN PLACE, CAUSING ME TO HIT, AND CRACK, THE WINDSHIELD, WITH THE LEFT FRONTAL ASPECT OF MY SKULL, RESULTING IN A CONCUSSION. THE DRIVER OF THE VEHICLE THAT RAN INTO ME, WAS TAKEN BY AMBULANCE TO THE HOSPITAL. WHILE MY CAR WAS AT THE COLLISION REPAIR CENTER, BEFORE IT WAS TAKEN TO SALVAGE, I WENT TO GATHER MY BELONGINGS THAT WERE INSIDE MY 4RUNNER. AT THE RECOMMENDATION OF MY LOCAL TOYOTA DEALER SERVICE MANAGER, I REPEATEDLY TESTED BOTH THE DRIVER, AND FRONT PASSENGER SHOULDER BELTS, BY ABRUPTLY AND RAPIDLY PULLING ON THEM. THE DRIVER SIDE BELT ONLY LOCKED IN PLACE ONCE, DURING APPROXIMATELY 10 TRIALS. THE PASSENGER SHOULDER BELT LOCKED IN PLACE EVERY TIME.