Narrative:

After landing on runway 19R at dulles (iad), we were cleared our aircraft from spot 70 to the gate. Via txwys a and A4. We proceeded east on taxiway a past taxiway A2. Per our chart we were looking for the first taxiway after A2 which would be A4. We came to a turnoff, turned right and proceeded to our gate without incident. Ramp control called and informed us that we had turned onto a vehicle roadway that was no longer a taxiway. At night this roadway looked like a taxiway. It would have helped us out if this roadway had been more clearly marked to differentiate it from a taxiway. This probably would not have happened during daylight hours. The subject roadway is approximately midway between txwys A2 and A4. Construction was underway in the vicinity, which caused us to reason that the taxiway sign was missing. We should have checked with ramp. Callback conversation with reporter revealed the following information: reporter from acn 501242 said the taxiway lines that were previously for the now abandoned taxiway are still visible if not too clear. They appear to be correct under night conditions. After parking, review with the controller indicated that this has happened before. The commercial chart that the crew was using gives no indication of the old taxiway or the fact that it is now a surface vehicle road.

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Original NASA ASRS Text

Title: AN ACR CREW TAKES A VEHICLE ROAD THAT HAS PREVOUSLY BEEN DESIGNATED A TXWY AS THE RTE TO THEIR TERMINAL AT IAD. CONSTRUCTION AND GND MARKING WERE FACTORS.

Narrative: AFTER LNDG ON RWY 19R AT DULLES (IAD), WE WERE CLRED OUR ACFT FROM SPOT 70 TO THE GATE. VIA TXWYS A AND A4. WE PROCEEDED E ON TXWY A PAST TXWY A2. PER OUR CHART WE WERE LOOKING FOR THE FIRST TXWY AFTER A2 WHICH WOULD BE A4. WE CAME TO A TURNOFF, TURNED R AND PROCEEDED TO OUR GATE WITHOUT INCIDENT. RAMP CTL CALLED AND INFORMED US THAT WE HAD TURNED ONTO A VEHICLE ROADWAY THAT WAS NO LONGER A TXWY. AT NIGHT THIS ROADWAY LOOKED LIKE A TXWY. IT WOULD HAVE HELPED US OUT IF THIS ROADWAY HAD BEEN MORE CLEARLY MARKED TO DIFFERENTIATE IT FROM A TXWY. THIS PROBABLY WOULD NOT HAVE HAPPENED DURING DAYLIGHT HRS. THE SUBJECT ROADWAY IS APPROX MIDWAY BTWN TXWYS A2 AND A4. CONSTRUCTION WAS UNDERWAY IN THE VICINITY, WHICH CAUSED US TO REASON THAT THE TXWY SIGN WAS MISSING. WE SHOULD HAVE CHKED WITH RAMP. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR FROM ACN 501242 SAID THE TXWY LINES THAT WERE PREVIOUSLY FOR THE NOW ABANDONED TXWY ARE STILL VISIBLE IF NOT TOO CLR. THEY APPEAR TO BE CORRECT UNDER NIGHT CONDITIONS. AFTER PARKING, REVIEW WITH THE CTLR INDICATED THAT THIS HAS HAPPENED BEFORE. THE COMMERCIAL CHART THAT THE CREW WAS USING GIVES NO INDICATION OF THE OLD TXWY OR THE FACT THAT IT IS NOW A SURFACE VEHICLE ROAD.

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.