I WAS DRIVING DOWN THE ROAD AT APPROX. 20 - 30 MPH. THERE WAS A VEHICLE IN FRONT OF ME. AS THE LIGHT TURNED FROM YELLOW TO RED, FIRST IT WAS GOING TO GO THROUGH THE LIGHT BUT THEN STOPPED. I SLAMMED ON MY BRAKES AND THE ABS BRAKES DID NOT WORK. MY BRAKES LOCKED AND I SKIDDED. FORTUNATELY, THE VEHICLE IN FRONT OF ME HEARD ME SQUEALING, AND STARTED EASING FORWARD. IT HAPPENED TO BE A TRUCK WITH A RECEIVER HITCH ON THE BACK. THAT'S WHAT I HIT, PUSHING HIM INTO THE INTERSECTION. HE WAS NOT HIT. THE PERSON I HIT TURNED OUT TO BE A POLICEMAN. *TR