Narrative:

Traffic was landing on runway 32L. There were numerous city construction vehicles working around the runway and they had been there for at least an hour before the event occurred. There were barricades on both sides of the runway, so as to prevent any construction vehicles from entering or crossing runway 32L. As air carrier X (DC9) was just about to touch down, the pilot initiated a go around on his own. A split second later the amass alarmed signifying traffic on the runway and issued go around instructions as well. Once the amass alarm had ceased. I issued go around instructions including a heading and altitude because it's very hard to talk over the very loud amass speakers. As air carrier X was going around, I noticed a city vehicle leaving the runway at the intersection of runway 32L and runway 27L. I contacted (via radio) the city construction coordinator who was working in the area of the construction and he was able to stop the vehicle that had just entered and exited the runway without a clearance and escorted the driver to a secure area. 3 mins later, air carrier Y (B747-400) was just about to touch down on the same runway and another, different, city construction vehicle entered the runway and caused the arrival to go around. The amass again alarmed after the pilot had already initiated the go around. A second city construction coordinating vehicle was able to stop this second vehicle that intruded on the runway and was able to secure this driver as well. As the second vehicle was being stopped, it again drove past the runway hold bars and stopped just short of the runway edge line. Traffic was on short final and I was about to send that traffic around as well, but the vehicle then backed away from the runway.

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Original NASA ASRS Text

Title: IN A 3 MIN PERIOD, AN ORD ATCT LCL CTLR HAS 2 GARS DUE TO RWY INCURSIONS BY VEHICLES IN 2 SEPARATE INSTANCES.

Narrative: TFC WAS LNDG ON RWY 32L. THERE WERE NUMEROUS CITY CONSTRUCTION VEHICLES WORKING AROUND THE RWY AND THEY HAD BEEN THERE FOR AT LEAST AN HR BEFORE THE EVENT OCCURRED. THERE WERE BARRICADES ON BOTH SIDES OF THE RWY, SO AS TO PREVENT ANY CONSTRUCTION VEHICLES FROM ENTERING OR XING RWY 32L. AS ACR X (DC9) WAS JUST ABOUT TO TOUCH DOWN, THE PLT INITIATED A GAR ON HIS OWN. A SPLIT SECOND LATER THE AMASS ALARMED SIGNIFYING TFC ON THE RWY AND ISSUED GAR INSTRUCTIONS AS WELL. ONCE THE AMASS ALARM HAD CEASED. I ISSUED GAR INSTRUCTIONS INCLUDING A HDG AND ALT BECAUSE IT'S VERY HARD TO TALK OVER THE VERY LOUD AMASS SPEAKERS. AS ACR X WAS GOING AROUND, I NOTICED A CITY VEHICLE LEAVING THE RWY AT THE INTXN OF RWY 32L AND RWY 27L. I CONTACTED (VIA RADIO) THE CITY CONSTRUCTION COORDINATOR WHO WAS WORKING IN THE AREA OF THE CONSTRUCTION AND HE WAS ABLE TO STOP THE VEHICLE THAT HAD JUST ENTERED AND EXITED THE RWY WITHOUT A CLRNC AND ESCORTED THE DRIVER TO A SECURE AREA. 3 MINS LATER, ACR Y (B747-400) WAS JUST ABOUT TO TOUCH DOWN ON THE SAME RWY AND ANOTHER, DIFFERENT, CITY CONSTRUCTION VEHICLE ENTERED THE RWY AND CAUSED THE ARR TO GO AROUND. THE AMASS AGAIN ALARMED AFTER THE PLT HAD ALREADY INITIATED THE GAR. A SECOND CITY CONSTRUCTION COORDINATING VEHICLE WAS ABLE TO STOP THIS SECOND VEHICLE THAT INTRUDED ON THE RWY AND WAS ABLE TO SECURE THIS DRIVER AS WELL. AS THE SECOND VEHICLE WAS BEING STOPPED, IT AGAIN DROVE PAST THE RWY HOLD BARS AND STOPPED JUST SHORT OF THE RWY EDGE LINE. TFC WAS ON SHORT FINAL AND I WAS ABOUT TO SEND THAT TFC AROUND AS WELL, BUT THE VEHICLE THEN BACKED AWAY FROM THE RWY.

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.