CAPT OF MLG WAS STOPPED BY GND CTLR INTERVENTION FROM TRANSGRESSING ACTIVE RWY AND A POSSIBLE COLLISION WITH ANOTHER ACFT ON ROLLOUT.

Narrative

AFTER PUSHBACK GND CTL CLRED US TO TAXI TO RWY 25R. AS WE BEGAN TAXI; MY FO NOTICED THAT THERE HAD BEEN A CHANGE IN THE SINGLE ENG PROCS WITH A L TURN AFTER DEP INSTEAD OF THE USUAL R TURN. I WAS DISCUSSING THE PROCS WITH HIM SO TO MEMORIZE IT BEFORE WE DEPARTED. I HAD BEEN IN AND OUT OF LAS JUST PRIOR TO THE REOPENING OF RWY 25R AND I WAS IN A WAY 'SPRING-LOADED' TO TAXI STRAIGHT AHEAD AND GO TO RWY 25L AS I HAD DONE THE LAST 2 MONTHS. WE WERE STILL DISCUSSING THE NEW PROCS AND I JUST CALLED FOR THE PRE TKOF CHKLIST WHEN GND CTL (ALMOST SIMULTANEOUSLY WITH MY HEAD LOOKING BACK TO THE L) SAID 'XXXX YOU BETTER STOP.' I STOPPED QUICKLY AND SMOOTHLY APPROX 20 FT FROM THE HOLD SHORT LINE FOR RWY 25R (TAXI SPD APPROX 10-12 KTS). AT THAT MOMENT A WHITE DC-9 ON ROLLOUT CROSSED IN FRONT OF US. GND THEN ASKED IF THEY HAD GIVEN US RWY 25R OR L AND I REPLIED RWY 25R. I MADE A L TURN DOWN THE TXWY TO THE DEP END OF RWY 25R. MANY THANKS TO THE GND CTLR (WHO I CALLED LATER) FOR KEEPING HIS EYES OPEN. FATIGUE; COMPLACENCY (DOING WHAT I HAD PREVIOUSLY DONE FOR 2 MONTHS); END OF DAY; DISTR OF NEW PROCS AND SEVERAL OTHERS ALMOST ADDED TO FILLING OUT A LOT OF RPTS AND POSSIBLY BENT METAL. WE MUST MAINTAIN PROPER VIGILANCE (HEADS UP AND OUTSIDE) DURING THE CRITICAL PHASE OF TAXIING.