LR31 FLT CREW TAXIING FOR DEP AT PIT ENTERS RWY WITHOUT CLRNC.

Narrative

I WAS CAPT ON A CPR FLT OUT OF PIT. MY FO WAS A QUALIFIED MULTI-THOUSAND FLT HR PLT WITH 5000+ HRS OF FLT INSTRUCTION GIVEN. WHILE PREPARING OUR AIRPLANE FOR FLT; OUR PAX UNEXPECTEDLY ARRIVED VIA VAN AT PLANE-SIDE. THEY WERE QUITE EARLY. NOT WANTING TO DISAPPOINT THEM; WE PACKED ALL OF THE BAGS AND SEATED EVERYONE AND STARTED ENGS. WE WERE CLRED TO TAXI TO RWY 28C VIA TXWY N AND TXWY E. RWYS 28C&R WERE THE ACTIVE RWYS PER THE ATIS. I HAD THE ARPT DIAGRAM IN FRONT OF ME AND INSTRUCTED MY FO TO TAXI TOWARD TXWY N4 AND TURN L ON TXWY N. I BELIEVED HE UNDERSTOOD ALL OF THE INSTRUCTIONS AS HE HEARD THE TAXI CLRNC; TOO. AS WE TAXIED OUT OF THE RAMP AREA TOWARD TXWY N4; I BEGAN TO COMPLETE OUR TAXI CHKS AND SET UP THE COCKPIT INSTS FOR TKOF. I WAS ALSO FIGURING OUR TKOF PERFORMANCE NUMBERS. AS I WAS IN THE MIDST OF FIGURING OUR TKOF PERFORMANCE; GND CTL CALLED OUR TAIL NUMBER AND STATED THAT WE WERE CURRENTLY ENTERING INACTIVE RWY 14/32 AT TXWY N4. HE SAID TO CONTINUE TAXIING DOWN THE RWY AND TURN L ON TXWY E. I APOLOGIZED TO THE CTLR; AND WE FOLLOWED HIS INSTRUCTIONS AND CONTINUED TO RWY 28C. WE; THE CREW; ALLOWED OUR EARLY ARRIVING PAX TO PRESSURE US INTO HURRYING; WHEN WE SHOULD HAVE TAKEN THE TIME NECESSARY TO COMPLETE CHKLISTS AND PERFORMANCE NUMBERS BEFORE LEAVING THE RAMP. I; THE CAPT; WHILE NOT FLYING; WAS NOT CONSTANTLY AWARE OF WHAT THE PF WAS DOING. (I HAD MY HEAD DOWN IN THE COCKPIT.) ANYONE IS CAPABLE OF MAKING MISTAKES; EVEN IF MY FO HAS OVER TWICE THE TOTAL FLT TIME AS I HAVE. I SHOULD NOT ASSUME THAT HE IS INCAPABLE OF MAKING THAT KIND OF MISTAKE. RWY 14/32 WAS NOT AN ACTIVE RWY AT THE TIME; BUT IF IT HAD BEEN ACTIVE; THIS COULD HAVE BEEN A VERY DANGEROUS SIT. HAVING HAD MY HEAD DOWN IN THE COCKPIT; AND NOT BEING FAMILIAR WITH PIT (MY FIRST TRIP THERE); I DON'T KNOW IF THE SIGNAGE IN THAT AREA OF TXWY N; TXWY N4; AND RWY 14/32 IS CONFUSING OR NOT. BUT MY CO-PLT WAS UNAWARE THAT HE HAD MISSED TXWY N WHEN HE ENTERED THE RWY.