FLT CREW OF B737 TAXIED TO AND ENTERED THE WRONG RWY AT AUS.

Narrative

ON PUSH CALL WERE TOLD TO EXPECT RWY 17R. ON TAXI WE WERE ISSUED RWY 35L. THERE WAS A COMPANY ACFT THAT HAD PUSHED AT THE SAME TIME AS US AND THEY WERE GIVEN RWY 35R. WE MADE A L TURN AND TAXIED VIA THE RAMP TOWARDS RWY 35L. I CALLED THE TWR AS WE APCHED THE END OF THE RWY. I SAID THAT WE WERE READY FOR TKOF AND WAS TOLD TO TAXI INTO POS AND HOLD RWY 35R. THE OTHER ACFT SAID THAT HE DID NOT MAKE THE CALL. TWR THEN ASKED WHICH RWY WE WERE SHORT OF AS HE DID NOT SEE ANYONE AT THE END OF RWY 35L. AT THIS POINT; BOTH OF US REALIZED THAT WE HAD TAXIED TO THE WRONG RWY. AS THE ACFT HAD TAXIED OVER THE BARS; WE MADE A 180 DEG TURN AND TAXIED CLEAR OF THE RWY. WE THEN CALLED GND AND TAXIED TO RWY 35L. THERE IS NO EXCUSE FOR WHAT WE HAD DONE AND BOILS DOWN TO SIMPLE COMPLACENCY. WE HAD FLOWN THIS PAIRING THE WHOLE MONTH AND ON EVERY TRIP IN AND OUT OF AUS HAD A S FLOW. WE ALLOWED OURSELVES TO GET INTO A RUT. ANOTHER CONTRIBUTING FACTOR WAS THAT GND SHOULD HAVE SEEN US MAKE THE WRONG TURN FROM THE RAMP AREA. ALSO; GND HAD NOT GIVEN US ANY SPECIFIC RTE TO TAKE TO THE RWY. ALTHOUGH A SIMPLE TAXI RTE; A SPECIFIC CLRNC WOULD HAVE CAUSED US TO THINK ABOUT FOLLOWING A SPECIFIC PATH AND WOULD HAVE RAISED OUR SITUATIONAL AWARENESS.