MD11 FLT CREW TURNS OFF THE RWY AT WRONG EXIT AND CROSSES THE CTRLINE OF AN INTERSECTING RWY CAUSING AN ACR TO INITIATE A GAR AT ORD.

Narrative

WE WERE INITIALLY GIVEN RWY HEADING AND 4000 FT; THEN A R TURN S AND HANDED OFF TO DEP CTL. DURING THIS VERY HIGH WORKLOAD TIMEFRAME (GAR AND VECTORS FOR THE NEW ILS); WE WERE ASSIGNED RWY 4R. I SWAPPED FMS FLT PLANS; RAN THE CHKLISTS AND THE FO DID AN EXCELLENT JOB FLYING THE ACFT. WE WERE VECTORED FAR INSIDE THE REQUIRED APCH GATE (IN MY ESTIMATION) FOR THE RWY 4R ILS; 1 1/2 MI OR SO FROM REKKS (4.2 MI FROM THE RWY) YET MANAGED TO BE CONFIGURED AND STABLE AT 1000 FT (AS OUR OPS MANUAL REQUIRES). THE TWR CLRED US TO LAND ON RWY 4R AND TOLD US TO 'ROLL IT TO THE END.' WE LANDED NORMALLY IN THE FIRST 2/3 OF THE TOUCHDOWN ZONE. ANY NOTES ABOUT THE RWY 4R TURNOFF RESTRS ON THE ATIS WERE NOT PRESENT FOR ME AT THIS POINT IN TIME DUE TO HIGH WORKLOAD. THE FO CHOSE TO DISENGAGE THE AUTOBRAKES JUST AFTER MAIN GEAR TOUCHDOWN AND APPLY MANUAL BRAKING. WE SLOWED RAPIDLY. NOT HAVING ANY KNOWLEDGE OF THE ORD RESTRS FOR RWY 9R AND TXWY Q OPS; I THOUGHT THAT 'ROLL IT TO THE END' WAS A COURTESY OPTION GIVEN TO US BY THE TWR (OFTEN GIVEN TO HVY JETS; ESPECIALLY WHEN THEIR PARKING AREA IS NEAR THERE); NOT AN ATC CLRNC REQUIRING US TO USE THE TXWY D EXIT AT THE END OF THE RWY. WE HAD SLOWED TO TAXI SPD UPON REACHING TXWY Q SO IN AN EFFORT TO REDUCE RWY OCCUPANCY TIME I MADE THE L TURN ONTO THE TXWY Q HIGH-SPD. WHILE HEADED FOR TXWY Q; MY FO DID STATE SOMETHING TO THE EFFECT THAT THE TWR WANTED US TO TURN OFF AT THE END. AS WE CLRED RWY 4R; I HEARD THE TWR ISSUE A B757 A GAR; STATING 'ACR X MADE A WRONG TURN.' I LOOKED BACK THINKING THAT PERHAPS I HAD NOT CLRED RWY 4R AND THAT CAUSED A RWY 4R GAR. INSTEAD; I SAW THAT WE WERE CLR OF RWY 4R AND WAS NOW LOOKING STRAIGHT DOWN RWY 27L (RWY 9R DEP END) AND SAW THE B757 BEGIN ITS CLB FROM APPROX 300-400 FT. I LOOKED DOWN AT MY ARPT DIAGRAM TO CONFIRM THAT I WAS NOT ON TXWY S (WHICH DOES CROSS THE END OF RWY 9R). WE WERE CLRLY ON TXWY Q AND CLR OF RWY 9R. CONFUSED; I CONTINUED TO OUR RAMP UNEVENTFULLY. I LATER CALLED THE TWR ON A LANDLINE AND WAS INFORMED THAT FAA REGION/ARPTS HAD CREATED THE RESTR ON SOME ACFT LNDG RWY 9R WHILE USING TXWY Q. TXWY Q DOES NOT INTERSECT RWY 9R (ONLY THE RWY EXTENDED CTRLINE). THE INDIVIDUAL ON THE PHONE TOLD ME THAT THEY (ATC) DISAGREED WITH THE RULE; BUT HAD TO ABIDE BY IT. I WAS INFORMED THAT NO LOSS OF SEPARATION HAD OCCURRED SO NOTHING WOULD BE DONE WITH OUR MISTAKEN EARLY RWY 4R TURNOFF. HE TOLD ME THAT TO THE TWR CAB IT APPEARED WE WERE STOPPING ON TXWY Q IN LINE WITH RWY 9R ALTHOUGH WE WERE STILL TAXIING AT APPROX 20 KTS DURING THIS TIMEFRAME. SUGGESTIONS: IF ATC NEEDS AN ACFT TO EXIT AT A PARTICULAR TURNOFF; THEN THE APPROPRIATE PHRASEOLOGY SHOULD BE USED. 'ROLL TO THE END' IS NOT AS CLR AS 'EXIT THE ACFT AT THE END OF THE RWY' OR 'EXIT ALL THE WAY AT THE END.' INFO DISSEMINATION OF THIS RWY 9R/TXWY Q LIMITATION WOULD FURTHER PROMPT CREWS TO BE MORE AWARE. WE NOW KNOW.