BRAKES FAILED AS I WAS GETTING ON FREEWAY. CARS HAD STOPPED AHEAD, I WAS PRESSING BRAKE PEDAL, CAR SLOWED A LITTLE BUT WOULD NOT STOP. I TRIED GETTING ONTO SHOULDER BUT CARS WERE GOING AROUND ME ONTO THE SHOULDER BECAUSE OF RUSH HOUR MORNING TRAFFIC. CONTINUED PRESSING BRAKE PEDAL WITH NO RESULTS. BRAKES FINALLY ENGAGED BUT LOCKED AND CAR SLID INTO 1999 LINCOLN, RESULTING IN FRONT-END DAMAGE. BRAKES WORKED AFTER CRASH. I CANNOT UNDERSTAND WHY THE BRAKES WOULD HAVE SUDDEN FAILURE AND THEN CONTINUE TO WORK. *AK