Narrative:

We had been cleared to taxi from spot X via taxiway wb to taxiway wc in iah. After looking at the chart and the signs marking the txwys, I followed what I thought was taxiway wb only to find myself on taxiway wa. The signs in iah are not labeled clearly and this is not the first time I have taken the wrong road. With my job I will fly into iah a couple of times in a month and then not again for another yr, which does not breed familiarity. The signs need additional arrows and better identify for clarification. On this same trip, as we started our takeoff roll in iah, the controller came on and cleared air carrier X for takeoff on runway 15R. Both myself and my first officer understood that we had already been cleared for takeoff. I queried the controller and he said that he was pretty sure that he had only cleared us into position and hold. Fortunately, the traffic was light and there were no conflicts. The first officer and I were both exhausted after dealing with WX and mechanicals for 2 days so several mistakes were made. It may be possible that we misunderstood, or heard the takeoff clearance we were expecting. With my first officer being totally unfamiliar with iah and myself being only slightly familiar, the taxiway incursion could have been avoided if the txwys were adequately labeled. Supplemental information from acn 556733: upon reaching the departure runway, tower issued us a 'cleared for takeoff.' I read back cleared for takeoff and completed the checklist. The captain gave me control of the aircraft and we began the takeoff roll. Before rotation, tower again said cleared for takeoff. While climbing out, we advised tower of our understanding of a prior takeoff clearance, but they did not comment. No conflicts existed and no more was said.

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Original NASA ASRS Text

Title: CL65 FLC FOLLOWED THE WRONG TXWY OUT AND TOOK OFF WITHOUT CLRNC.

Narrative: WE HAD BEEN CLRED TO TAXI FROM SPOT X VIA TXWY WB TO TXWY WC IN IAH. AFTER LOOKING AT THE CHART AND THE SIGNS MARKING THE TXWYS, I FOLLOWED WHAT I THOUGHT WAS TXWY WB ONLY TO FIND MYSELF ON TXWY WA. THE SIGNS IN IAH ARE NOT LABELED CLRLY AND THIS IS NOT THE FIRST TIME I HAVE TAKEN THE WRONG ROAD. WITH MY JOB I WILL FLY INTO IAH A COUPLE OF TIMES IN A MONTH AND THEN NOT AGAIN FOR ANOTHER YR, WHICH DOES NOT BREED FAMILIARITY. THE SIGNS NEED ADDITIONAL ARROWS AND BETTER IDENT FOR CLARIFICATION. ON THIS SAME TRIP, AS WE STARTED OUR TKOF ROLL IN IAH, THE CTLR CAME ON AND CLRED ACR X FOR TKOF ON RWY 15R. BOTH MYSELF AND MY FO UNDERSTOOD THAT WE HAD ALREADY BEEN CLRED FOR TKOF. I QUERIED THE CTLR AND HE SAID THAT HE WAS PRETTY SURE THAT HE HAD ONLY CLRED US INTO POS AND HOLD. FORTUNATELY, THE TFC WAS LIGHT AND THERE WERE NO CONFLICTS. THE FO AND I WERE BOTH EXHAUSTED AFTER DEALING WITH WX AND MECHANICALS FOR 2 DAYS SO SEVERAL MISTAKES WERE MADE. IT MAY BE POSSIBLE THAT WE MISUNDERSTOOD, OR HEARD THE TKOF CLRNC WE WERE EXPECTING. WITH MY FO BEING TOTALLY UNFAMILIAR WITH IAH AND MYSELF BEING ONLY SLIGHTLY FAMILIAR, THE TXWY INCURSION COULD HAVE BEEN AVOIDED IF THE TXWYS WERE ADEQUATELY LABELED. SUPPLEMENTAL INFO FROM ACN 556733: UPON REACHING THE DEP RWY, TWR ISSUED US A 'CLRED FOR TKOF.' I READ BACK CLRED FOR TKOF AND COMPLETED THE CHKLIST. THE CAPT GAVE ME CTL OF THE ACFT AND WE BEGAN THE TKOF ROLL. BEFORE ROTATION, TWR AGAIN SAID CLRED FOR TKOF. WHILE CLBING OUT, WE ADVISED TWR OF OUR UNDERSTANDING OF A PRIOR TKOF CLRNC, BUT THEY DID NOT COMMENT. NO CONFLICTS EXISTED AND NO MORE WAS SAID.

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.