DC9 CREW ENTERED THE RWY STOPWAY FOR RWY 27 AT BOS.

Narrative

I WAS THE PIC AND PF ON THIS FLT. I LANDED ON RWY 27 IN BOS AND HAD INTENTIONS OF TURNING OFF ON TXWY W OR TXWY S. LNDG WAS SMOOTH AND IN THE TOUCHDOWN ZONE WITH A NORMAL ROLLOUT. I WAS FOCUSED ON TURNING OFF ON THE LAST TXWY. I QUICKLY GLANCED DOWN AT MY TAXI CHART WHILE I WAS AT TAXI SPD AFTER THE ROLLOUT AND WHILE DOING SO; MISSED TXWY W AND TXWY S AND TAXIED ONTO RWY 27 STOPWAY. THE FO DID MENTION THAT WE NEEDED TO TURN OFF; AND AT THE SAME TIME I REALIZED I PASSED THE LAST EXIT. AS PER TWR INSTRUCTIONS; I STOPPED ON THE STOPWAY; WAS HANDED OFF TO GND CTL WHO THEN HAD US CONTINUE ON THE STOPWAY TO JOIN TXWY B AND TXWY A TO OUR GATE. I WAS INSTRUCTED TO CALL THE TWR ON THE PHONE AFTER OUR AR AT THE GATE; WHICH I DID AND GAVE HIM ALL THE INFO HE ASKED FOR. AS PER MY APCH BRIEF; I HAD DISCUSSED TURNING OFF ON TXWY W OR TXWY S. SUPPLEMENTAL INFO FROM ACN 485880: WE LANDED ON RWY 27 AT BOS. I WAS THE PNF. THE CAPT TOUCHED DOWN ON THE TOUCHDOWN MARKERS. THE TURNOFF THAT WE USUALLY AIM TO USE IS TXWY W. THIS TURNOFF IS THE LAST EXIT FOR RWY 27. THE ROLLOUT WAS SMOOTH AND SPD WAS A SLOW TAXI. AS WE APCHED TXWY W; I HAD ASSUMED THAT THE CAPT WOULD MAKE THE TURN AT TXWY W. I LOOKED TO MY R TO CLR THE AREA FOR THE TURN AND WHEN I RETURNED TO A FORWARD VIEW; I REALIZED WE WERE NOT TURNING. I THEN SAID 'WE NEED TO TURN.' IT WAS TOO LATE. WE TAXIED ONTO THE RWY 27 STOPWAY; AS THE TWR ALSO SAID TO STOP. THE CAPT THEN 'AS PER TWR INSTRUCTION' CONTINUED TO TAXI ON THE STOPWAY TO THE END WHICH JOINED TXWY B. THE CAPT IN DISCUSSION WITH ME SAID THAT HIS FOCUS WAS ON THE TURN AT THE END AND NOT ON TXWY W; AND THAT WITH THE 1700 FT OF STOPWAY IT APPEARED AS IF HE HAD MORE TO GO. UNFORTUNATELY; AFTER TXWY W THERE IS NO ROOM BTWN IT AT THE START OF THE STOPWAY; LEAVING LITTLE TIME FOR ME TO HAVE PREVENTED FURTHER MOVEMENT BEFORE THE STOPWAY; WHEN I SPOKE UP. THE STOPWAY HAD A LARGE BREAK BTWN THE TOUCHDOWN LIGHTS. NO LIGHTS WERE HIT. I ASSUME THIS ALSO GAVE THE ILLUSION TO THE CAPT THAT THE RWY CONTINUED. ON APCH WE HAD BRIEFED THE TURNOFF.