NORTHBOUND TRAIN WAS CONDUCTING A CREW TRANSFER AND WAS IN A STOPPED MODE OVER THE PARK AVENUE CROSSING. DURING THE TRANSFER, A WESTBOUND AUTO CAME TO A STOP AT THE AUTOMATED GATE ARMS, WHERE THE GATES HAD RED FLASHING LIGHTS, RED WIG WAG LIGHTS ON THE SIGNAL MAST AND A RINGING BELL ON THE SIGNAL MAST. ALL LIGHTS AND GATES WERE FULLY FUNCTIONAL. AFTER THE VEHICLE CAME TO A STOP, THE DRIVER FELLASLEEP AT THE WHEEL AND HIS FOOT RELEASED THE BRAKE PEDAL CAUSING HIM TO ROLL INTO THE SIDE OF TRAI