FLC FAILS TO COMPLY WITH TWR HOLD SHORT INSTRUCTIONS.

Narrative

AFTER LNDG ON RWY 22L AT BOSTON-LOGAN; WHILE STILL ON THE LNDG ROLL; WE WERE ISSUED TAXI INSTRUCTIONS. AFTER EXITING THE RWY ON ASSIGNED TXWY; WE BEGAN AFTER LNDG CHKLISTS. (THE CREWS FROM OUR DOMICILE GO INTO BOSTON- LOGAN ONLY 1 TIME PER WEEK AND NOT NECESSARILY THE SAME CREW.) AS WE FINISHED THE AFTER LNDG CHKLISTS WE WERE ARRIVING AT THE DEP END OF RWY 22R WHERE TXWY C CROSSES. BY THE TIME ALL NECESSARY CHKS WERE COMPLETED AND BOTH MEMBERS OF FLC FOCUSED ATTN OUTSIDE; WE REALIZED WE HAD ROLLED ONTO RWY 22R. TWR IMMEDIATELY TOLD US TO HOLD AT THE SAME TIME AS I APPLIED BRAKES AND COUNTER THRUST TO STOP ACFT. ONLY THE NOSE OF ACFT; NOT ENTIRE ACFT; PROTRUDED INTO RWY; HOWEVER; WE WERE PAST HOLD LINE. I WAS ABLE TO BACK ACFT FROM PROTRUDING INTO RWY; HOWEVER; ANOTHER ACFT HAD THEIR TKOF CLRNC CANCELED AND HAD TO REPOSITION FOR TKOF. NEITHER ACFT WERE EVER CLOSER THAN PLUS OR MINUS 5000 FT FROM EACH OTHER. AT THAT POINT WE WERE CLRED ACROSS RWY 22R AND INSTRUCTED TO CONTACT GND AND THE TAXI TO THE RAMP WAS UNEVENTFUL. I WAS INSTRUCTED TO CONTACT TWR ONCE INSIDE OPS; WHO SUBSEQUENTLY INSTRUCTED ME TO CONTACT BOSTON FAA; WHICH I DID. IT IS MY BELIEF THAT THE INFREQUENT TRIPS INTO BOSTON-LOGAN BY THIS CREW WAS A SIGNIFICANT FACTOR IN THIS SIT ALONG WITH THE COMPLICATED RWY/TXWY LAYOUT OF BOSTON-LOGAN ARPT. IT WOULD SEEM THAT IT WOULD BE BENEFICIAL IF ACFT WERE ALLOWED TO EXIT THE RWY; COME TO A COMPLETE STOP AND ALLOWED TO COMPLETE ANY CHKLISTS NECESSARY BEFORE CONTINUING THEIR TAXI ALLOWING BOTH CREW MEMBERS TO FOCUS THEIR COMPLETE ATTN OUTSIDE OF THE ACFT. THIS WOULD ALLOW FOR CREWS WHO ARE NOT AS FAMILIAR TO KEEP TRACK OF THEIR SURROUNDINGS. I UNDERSTAND THAT THIS IS NOT A PRACTICAL SOLUTION FOR AN ARPT AS BUSY AS BOSTON IS.