AN ACR LGT TAXIED JUST OVER THE HOLD SHORT LINE.

Narrative

WE WERE INSTRUCTED BY TWR TO EXIT AT TXWY 36. IN THE CAPT'S JUDGEMENT (CAPT WAS PF); HE WAS GOING TOO FAST AND ELECTED TO TURN OFF ON THE SUBSEQUENT TXWY -- NUMBER 42. AS WE MADE THE TURNOFF; WE WERE INSTRUCTED TO HOLD SHORT OF RWY 25R AND REMAIN ON TWR FREQ. I READ BACK THE CLRNC AND ASSUMED THE CAPT HAD UNDERSTOOD THE CLRNC. AS WE APCHED THE HOLD LINE; I NOTICED HE WASN'T STOPPING. I LOOKED AT HIM AND BEGAN TO SPEAK. AT THIS POINT; HE IMMEDIATELY STOPPED THE ACFT -- PAST THE HOLD LINE; BUT SHORT OF THE RWY EDGE. AN MLG WAS ON TKOF ROLL AND CONTINUED A NORMAL TKOF. THE CAPT LATER EXPLAINED THAT; ALTHOUGH HE HAD HEARD THE CLRNC; HE HAD BECOME MOMENTARILY CONFUSED ABOUT OUR POS. THERE WERE NEW MARKINGS; SOME CONSTRUCTION; AND HE WAS TRYING TO PLOT A COURSE TO OUR GATE. FOR MY PART; I WAS STARTING THE APU AND LOOKING OUT THE R WINDOW TO CHK 25R. I SHOULD HAVE INITIALLY OBTAINED A CLR ACKNOWLEDGMENT FROM THE CAPT THAT WE HAD BEEN INSTRUCTED TO HOLD SHORT. ONE OTHER POINT IS THAT; WHEN ATC ISSUES AN INSTRUCTION DURING LNDG ROLLOUT; IT IS ALMOST A SURE THING THAT SOMEONE IN THE COCKPIT WILL NOT UNDERSTAND IT DUE TO THE HIGH DEG OF CONCENTRATION ON ACFT CTL.