IN AN ACCIDENT WHERE I WAS THE AT FAULT DRIVER, I WAS APPROACHING A STOP LIGHT AND DID NOT NOTICE THE RED LIGHT NOR THE CAR STOPPED UNTIL APPROXIMATELY THREE SECONDS BEFORE IMPACT. ONCE I RECOGNIZED WHAT WAS HAPPENING, I IMMEDIATELY SLAMMED ON THE BREAKS. I HIT THE OTHER DRIVER IN THE REAR OF HIS VEHICLE. AS STATED ABOVE, I HIT MY BREAKS ABOUT 3 SECONDS BEFORE IMPACT, BUT MY ABS DID NOT ACTIVATE; INSTEAD MY BREAKS LOCKED AND I SLID 15-30 FEET INTO THE OTHER VEHICLE. ADDITIONALLY, SINCE MY AIRBAGS DEPLOYED, A TOW TRUCK WAS REQUIRED TO TOW MY TRUCK. UPON ARRIVAL OF THE TOW, MY TRUCK WOULD NOT START, SO HE NEEDED TO PULL IT UP ONTO THE BED OF HIS TOW TRUCK WITH CHAINS. ONCE HOOKED UP, HE BEGAN TO DRAG THE TRUCK UP. THE TOW DRIVER ASKED ME IF THE TRUCK WAS 4 WHEEL DRIVE AND WHETHER I HAD BEEN DRIVING IN 4 WHEEL. I INDICATED IT DID, BUT I WAS NOT DRIVING IN 4 WHEEL MODE. I ASKED WHY HE HAD ASKED, AND HE SAID THAT IT WHILE PULLING THE TRUCK UP, ALL FOUR WHEELS WERE LOCKED. HE SAID THAT SHOULD NOT HAPPEN NORMALLY. I'M NOT SURE EXACTLY HOW THE MECHANICS OF ABS WORK, BUT I HAVE FELT ABS ENGAGE MULTIPLE TIMES AND HAVE ATTENDING DRIVERS TRAINING FOR WINTER WEATHER CONDITIONS. MY ABS DID NOT ACTIVATE; THERE WAS NO STUTTER OF THE BREAKS, ONLY A STABLE PRESS WITH NO ACTIVE RESPONSE OTHER THAN LOCKED BREAKS AND A LONG SKID.