B757 MAINT CREW WHILE TAXIING FOR AN ENG TEST RUN HAS A RWY INCURSION AT LAS.

Narrative

WHILE TAXIING TO AN APPROVED ENG RUN AREA TO DO AN ENG RUN; I HAD PROBS WITH FINDING THE TXWY TURNOFFS DUE TO UNFAMILIARITY WITH THE TXWY SYS LAYOUT. I AM AN ACFT INSPECTOR FERRIED OUT OF ZZZ1. I HAD OVERRUN THE FIRST TURNOFF DUE TO MISUNDERSTANDING THE RADIO OPERATOR'S INSTRUCTIONS ASSUMING THE TURNOFF WAS THE FOLLOWING TXWY. AT THIS POINT I SHOULD HAVE ASKED FOR 'PROGRESSIVE TAXI INSTRUCTIONS' BUT WAS UNAWARE OF THE PROC AT THE TIME. THE TWR TRIED AGAIN TO MARSHALL ME TO THE RUN-UP AREA BUT AGAIN I MISSED THE SECOND TURNOFF AND HAD TO HOLD SHORT OF AN ACTIVE RWY. THIS OCCURRED AT PRIME MORNING LAUNCH TIME XA30 AM WHERE TFC IS HVY. I WAS INFORMED THAT I WAS NOSED OVER THE HOLD SHORT LINE AND THAT AN ACFT INCURSION HAD OCCURRED BY A LNDG ACFT. UPON RECEIVING THE PROGRESSIVE TAXI INSTRUCTIONS I WAS ABLE TO GET TO THE ENG RUN AREA AND COMPLETE THE TASK. FACTORS THAT LED TO THIS SIT WERE UNFAMILIARITY WITH THE ARPT; MISCOM WITH MY R SEAT RADIO MAN (WHO WAS THE LCL STATION MGR); THE RISING SUN ALSO MADE READING TXWY SIGNS DIFFICULT TO DECIPHER. ALTHOUGH QUALIFIED AND TRAINED IN TAXI PROCS IT IS NOT PART OF MY EVERY DAY DUTIES AND I OFTEN GO MONTHS WITHOUT TAXIING AN ACFT AND THEREFORE I AM NOT AS PROFICIENT AS I'D LIKE TO BE. THE RADIO MAN DID A GOOD JOB OF CALLING OUT TXWYS BUT NOT BEING FAMILIAR WITH THE ARPT; PROGRESSIVE TXWY INSTRUCTIONS WOULD HAVE WORKED BETTER. THERE WERE NO LCL MECHS AVAILABLE TO TAXI THE ACFT FOR ME; HENCE THE STATION MGR RIDING R SEAT FOR THE TAXI/ENG RUN. THERE WAS NO ACFT DAMAGED OR ACCIDENT OF ANY TYPE. THE INCURSION WAS CAUSED BY BEING NOSED OVER THE RWY HOLD LINE.