C402 PENETRATED THE ACTIVE RWY AS A CL65 WAS TAKING OFF.

Narrative

THE PROB AROSE WHEN I TAXIED ONTO AN ACTIVE RWY. I RECEIVED A CLRNC TO TAXI TO RWY 22R VIA TXWY A; THEN TXWY N; ACROSS RWY 33L AT BOS. UPON RECEIPT OF MY CLRNC; I BEGAN TO TAXI ON TXWY A UNTIL I APCHED AN ACFT BLOCKING THE ENTRANCE TO TXWY. I WAS THEN TOLD TO JOIN TXWY K; AND CROSS RWY 33L; AND TO MONITOR 128.8. AT THIS POINT; I SAW A BLACK SIGN WITH YELLOW MARKINGS LABELED 'TXWY K' TO MY R. I MADE THE R TURN ONTO WHAT I THOUGHT WAS TXWY K; BUT WAS ACTUALLY TXWY T. I CONTINUED TO TAXI ON WHAT I THOUGHT WAS TXWY K; BUT IN REALITY WAS TXWY T. I APCHED THE RWY INTXNS OF RWY 22R AND RWY 33L; AND PERCEIVED THE SIGNS OF RWY 33L AT THIS POINT TO BE THE POINT AT WHICH I WAS CLRED TO CROSS. AS THE NOSE OF THE ACFT BEGAN ACROSS THE RWY EDGE MARKINGS OF RWY 22R; I DISCOVERED THE ERROR. I LOOKED DOWN THE RWY; AND SAW THE LIGHTS OF AN ACFT (TYPE UNKNOWN) BEGINNING ITS TKOF ROLL. AT THIS POINT; THE NOSE OF MY ACFT WAS ACROSS THE RWY EDGE MARKING; AND I ELECTED TO MAKE THE APPROX 120 DEG L TURN ONTO RWY 33L TO VACATE THE ACTIVE RWY AS QUICKLY AS POSSIBLE. I THEN STOPPED THE ACFT; AND FURTHER INSTRUCTION FROM GND CTL WAS RECEIVED. CONTRIBUTING FACTORS TO THIS ERROR ARE THE COMPLICATED INTXNS OF TXWY T; TXWY Q; AND TXWY K; AND THE INTXNS OF RWY 22R AND RWY 33L -- IN VERY CLOSE PROX TO EACH OTHER. THE ERROR WAS DISCOVERED WHEN I NOTICED THE RWY I HAD ENTERED WAS NOT RWY 33L; BUT THE ACTIVE RWY; RWY 22R. A POSSIBLE CORRECTIVE ACTION WOULD BE BETTER LIGHTING AND TXWY MARKINGS PAINTED ON THE PAVEMENT TO ASSIST AND CLARIFY THE MARKINGS AND TXWYS. SUPPLEMENTAL INFO FROM ACN 568933: UPON TKOF ROLL ON RWY 22R IN BOS; AT APPROX 100 KTS; THE TWR CTLR CALLED OUR CALL SIGN; BUT NO FURTHER ADVISORY. I; THE CAPT; PNF; RESPONDED 'WE'RE ROLLING' AND THOUGHT NO FURTHER ABOUT IT. NO INCURSION WAS SEEN BY EITHER ME OR MY FO. AFTER TKOF; THE TWR ASKED US TO CALL THEM UPON ARR IN JFK. WE DID AND WERE INFORMED THAT A TWIN CESSNA HAD PULLED IN FRONT OF US; ON THE RWY AS WE ROTATED. NO ACTION WAS PERFORMED BY US AS WE DID NOT SEE; HEAR OR PERCEIVE ANY IRREGULARITY. EXCEPTING THE TWR CALL AS WE ACCELERATED THROUGH 100 KTS; NOTHING ALERTED US TO AN INCURSION OR DANGER.