"Do not enter Taxiway R; Turn around; Go back to 98th; Clearance required for red or red striped badges to proceed," one sign reads.
On the other side of the taxiway, the new sign at the road's intersection with the runway has an even more dire message: "Danger. Do not enter."
The 4-foot-by-8-foot sign designating "Runway 8-26" in large white letters on a bright red background also warns: "If lost, stay here, contact your supervisor."
DIA has installed these large billboard-style warning signs wherever roads for airport vehicles meet runways, Kinney said.
Airport workers also painted large red-and-white "35 L - 17 R" signs on the pavement at a "holdbar" - painted markings that require air-traffic-control authority to cross - just before Taxiway EC crosses Runway 35 left/17 right.
On July 31, a DIA electrician mistakenly turned onto EC from an access road, thinking it was a different taxiway farther north.
On EC, the maintenance employee, without permission, crossed the holdbar and then sped across the runway as a United jet was getting into position for takeoff, according to an FAA report on the incident.
The United plane had not started its takeoff roll, so the FAA recorded it as a Category D incursion - one in which there is "little or no chance of collision."
In addition to DIA's two near-collisions, the airport had one other Category D incursion in the recent year.
Last month, FAA acting administrator Bobby Sturgell said his agency would target Category C and D incursions as "precursors" of more serious events.
FAA requires upgrades
To help ensure that pilots stop and get controller permission to enter runways, the FAA has mandated that airports paint extra-wide enhanced taxiway centerline markings to denote the final 150 feet leading up to runway holdbars.
Airports must have the new markings in place by June.
DIA already has completed the task of painting the wider taxiway centerline at 92 runway intersections, Kinney said.
The FAA-led runway-safety meeting in October found that DIA's spacious layout - with no intersecting runways and plenty of separation between them - meant the airport was at a low risk for "wrong runway departures."
It decided "airport complexity" was DIA's only risk factor.
The airport hopes to soon get an updated safety technology called Airport Surface Detection Equipment, Model X, which is designed to give tower controllers early warning of impending collisions between aircraft, or between planes and transponder-equipped vehicles.
In the serious incursions at DIA this year involving the small cargo plane and the snowplow, the tower's existing collision-sensing technology did not warn controllers in a timely way, according to NTSB reports.
Controllers say the tower's shortage of radar displays for the current collision-avoidance system contributed to the incursion involving the small cargo plane in January.
On Thursday, the NTSB's board recommended that the aviation industry develop devices that provide "a direct warning to the cockpit" of a looming collision.
"A system being installed at airports by the FAA provides warning to air traffic controllers, but not to the flight crews," the NTSB said, "a situation that greatly reduces the amount of time that pilots have to react to an impending incursion."
EDITORIAL Bump safety at DIA to first class The airport is in line to get an upgraded tracking system by 2009, but two close calls point out the urgency of the situation.
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