DURING TAXI FOR TKOF; CREW TAXIED ONTO ACTIVE RWY.

Narrative

AFTER ENG START; WE WERE GIVEN TAXI INSTRUCTIONS FROM GATE TO TAXI TO RWY 8L. BOTH CREW MEMBERS HAD THEIR RESPECTIVE ONT 10-9 PAGES OUT AND IN VIEW. PRETKOF CHKLIST WAS ACCOMPLISHED WHILE TAXIING. AT ABOUT THE TIME WE WERE PASSING INTXN L; THE TWR CTLR ASKED US IF WE COULD TAKE RWY 8L DEP AT INTXN D. WE THEN BOTH BEGAN TO CHK THE 10-9 PAGE FOR WHERE TXWY D WAS LOCATED. TWR THEN ADDED THAT IT WOULD BE THE SAME DISTANCE AS RWY 8R. WE STATED THAT WE WERE PRETTY SURE THAT WE COULD USE THAT INTXN AND HE STATED TO CONTINUE TO TAXI TO RWY 8L INTXN D. THE FO THEN PULLED OUT THE PERFORMANCE COMPUTER AND BEGAN TO CHK THOSE NUMBERS. I CONTINUED TO LOOK AT THE 10-9 PAGE LOOKING FOR THE INTXN OF N AND D AS WE APCHED THE AREA OF INTERSECTING TXWY F; K; G; AND N. I SAW ON THE 10-9 PAGE WHAT I INTERPRETED AS A SLIGHT JOG TO THE L IN TXWY N IN THIS AREA. AS I LOOKED FORWARD; I SAW WHAT APPEARED TO ME TO BE SOME KIND OF ROADWAY WITH NUMEROUS LARGE AREAS OF MACADAM PATCHING. THE AREA RIGHT IN FRONT OF ME WAS; AS I REMEMBER; ALSO A DIFFERENT COLOR THAN THE TXWY THAT I WAS CURRENTLY ON. I BELIEVE THIS REINFORCED MY LOOKING FOR A SLIGHT L JOG IN TXWY N AND THAT THE AREA DIRECTLY IN FRONT OF ME WAS NOT A TXWY. I DID NOT SEE ANY SIGNS FOR TXWY N IN THIS AREA. I DID NOT SEE A YELLOW RWY HOLD SHORT MARKING ON THE TXWY; NOR DID I SEE A RED RWY 8L/26R RWY MARKING BOX. I DO NOT DOUBT THAT THEY MUST BE THERE -- I JUST DID NOT SEE THEM. I MADE THE SLIGHT L JOG THAT I WAS LOOKING FOR AND CONTINUED TO TAXI FORWARD (W); ON WHAT I THOUGHT WAS TXWY N. AT ABOUT THIS TIME THE FO REPLACED THE PERFORMANCE COMPUTER; SAID THAT WE COULD USE INTXN D; AND CALLED THE TWR SO STATING. I THINK WE BOTH REALIZED THAT SOMETHING WAS JUST NOT RIGHT AT ABOUT THE SAME TIME. WE REALIZED THAT WE WERE NOT ON TXWY N; BUT WERE ACTUALLY TAXIING W DOWN RWY 8 TOWARDS THE D INTXN. WE IMMEDIATELY ASKED TWR FOR TKOF CLRNC AND RECEIVED IT. THERE WERE NO CONFLICTS WITH ANY OTHER ACFT. WE DID A 180 DEG TURN ON THE RWY AND DEPARTED. NOTHING WAS STATED BY ANY OF THE TWR PERSONNEL.