Narrative:

While on final approach in night VFR conditions, I was the first officer flying the aircraft, flight air carrier X dca-ord. We were landing runway 4R at ord and on final we were instructed to roll to the end, which is standard for runway 4R arrs at ord. The landing was uneventful. However, as I was transitioning control of the aircraft to the captain, the ord tower controller, in rapid cadence, informed us to turn off and contact ground 121.9. I was never clear if he said 'expedite' or 'next turn' or 'roll to the end' but due to the night conditions and my perceived sense of urgency, I applied slight left rudder pressure in anticipation of our left turnoff, and then relinquished control of the aircraft to the captain. I personally was unsure of our exact location relative to the end of the runway and the subsequent turnoff. However, as the captain turned off I think we both realized we had made an early turnoff. The captain stopped the aircraft on the taxiway clear of runway 4R. Tower then told us we were not supposed to turn off there, but to go ahead and taxi straight ahead and contact ground point 9. There was never any conflict with other traffic and no more was said. It turns out that we exited on a new taxiway (S5) that was constructed as a result of the new runway 27L holding/deicing pad within the last yr. On my next trip (3 days later) the paperwork included a message to be aware of an early turnoff on the same taxiway (S5) we turned off on, and that such a move is considered to be a runway excursion of runway 9R/27L. I believe that night visibility, inadequate runway lighting, and the tower controller's 'hustle up' verbiage during what is always a critical phase of flight while we were still on the runway contributed to our subsequent error.

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Original NASA ASRS Text

Title: FLC OF AN LGT ACR ACFT INADVERTENTLY TURNED OFF RWY TOO SOON AFTER LNDG ONTO A NEW TXWY RESULTING IN A RWY EXCURSION.

Narrative: WHILE ON FINAL APCH IN NIGHT VFR CONDITIONS, I WAS THE FO FLYING THE ACFT, FLT ACR X DCA-ORD. WE WERE LNDG RWY 4R AT ORD AND ON FINAL WE WERE INSTRUCTED TO ROLL TO THE END, WHICH IS STANDARD FOR RWY 4R ARRS AT ORD. THE LNDG WAS UNEVENTFUL. HOWEVER, AS I WAS TRANSITIONING CTL OF THE ACFT TO THE CAPT, THE ORD TWR CTLR, IN RAPID CADENCE, INFORMED US TO TURN OFF AND CONTACT GND 121.9. I WAS NEVER CLR IF HE SAID 'EXPEDITE' OR 'NEXT TURN' OR 'ROLL TO THE END' BUT DUE TO THE NIGHT CONDITIONS AND MY PERCEIVED SENSE OF URGENCY, I APPLIED SLIGHT L RUDDER PRESSURE IN ANTICIPATION OF OUR L TURNOFF, AND THEN RELINQUISHED CTL OF THE ACFT TO THE CAPT. I PERSONALLY WAS UNSURE OF OUR EXACT LOCATION RELATIVE TO THE END OF THE RWY AND THE SUBSEQUENT TURNOFF. HOWEVER, AS THE CAPT TURNED OFF I THINK WE BOTH REALIZED WE HAD MADE AN EARLY TURNOFF. THE CAPT STOPPED THE ACFT ON THE TXWY CLR OF RWY 4R. TWR THEN TOLD US WE WERE NOT SUPPOSED TO TURN OFF THERE, BUT TO GO AHEAD AND TAXI STRAIGHT AHEAD AND CONTACT GND POINT 9. THERE WAS NEVER ANY CONFLICT WITH OTHER TFC AND NO MORE WAS SAID. IT TURNS OUT THAT WE EXITED ON A NEW TXWY (S5) THAT WAS CONSTRUCTED AS A RESULT OF THE NEW RWY 27L HOLDING/DEICING PAD WITHIN THE LAST YR. ON MY NEXT TRIP (3 DAYS LATER) THE PAPERWORK INCLUDED A MESSAGE TO BE AWARE OF AN EARLY TURNOFF ON THE SAME TXWY (S5) WE TURNED OFF ON, AND THAT SUCH A MOVE IS CONSIDERED TO BE A RWY EXCURSION OF RWY 9R/27L. I BELIEVE THAT NIGHT VISIBILITY, INADEQUATE RWY LIGHTING, AND THE TWR CTLR'S 'HUSTLE UP' VERBIAGE DURING WHAT IS ALWAYS A CRITICAL PHASE OF FLT WHILE WE WERE STILL ON THE RWY CONTRIBUTED TO OUR SUBSEQUENT ERROR.

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.