Narrative:

I was working local control and cleared small aircraft X for takeoff. Ground control told FAA vehicle to hold short runway 33R. Car crossed runway 33R in front of departing aircraft. It was too late to stop small aircraft X. FAA vehicle said he thought he was supposed to hold at runway 15R. No action was taken. Supervisors were aware of incident.

Google
 

Original NASA ASRS Text

Title: VEHICLE NON ADHERENCE TO ATC INSTRUCTION CROSSED ACTIVE RWY IN FRONT OF SMA X ON TKOF. RWY INCURSION.

Narrative: I WAS WORKING LCL CTL AND CLRED SMA X FOR TKOF. GND CTL TOLD FAA VEHICLE TO HOLD SHORT RWY 33R. CAR CROSSED RWY 33R IN FRONT OF DEPARTING ACFT. IT WAS TOO LATE TO STOP SMA X. FAA VEHICLE SAID HE THOUGHT HE WAS SUPPOSED TO HOLD AT RWY 15R. NO ACTION WAS TAKEN. SUPVRS WERE AWARE OF INCIDENT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.