TAXIING FROM THE DE-ICE PAD WITHOUT A CLRNC; FLT CREW OF E145 GET STUCK IN SNOW DRIFTS AND BLOCK ACCESS TO DEP RWY AT PIT.

Narrative

AFTER BEING DE-ICED; I SIGNALED THE GND MARSHALER THAT I WAS READY TO TAXI. MY INTENT WAS TO REMAIN ON THE EDGE OF THE 'C' DE-ICE PAD. DUE TO THE SNOW ACCUMULATION; I INADVERTENTLY TAXIED THE NOSE OF THE ACFT OUT ONTO TXWY B. THERE WAS AN ACR ACFT ON TXWY B BTWN TXWY V AND TXWY T WHO DID NOT BELIEVE THAT HE COULD GET BY. AS I WAS REPOSITIONING MY ACFT OUT OF THE WAY AND BACK INTO THE PAD; THE GND CTLR CHANGED HIS INSTRUCTIONS AND WANTED ME TO PULL BACK ONTO TXWY B AND THEN A L ONTO TXWY B2 TO ALLOW OTHER ACFT TO PASS. I PULLED THE ACFT BACK ONTO THE CTR OF THE TXWY. MY NOSEWHEEL GOT STUCK IN A DRIFT OF SNOW AND WOULD NOT EFFECT A TURN. I STOPPED AND SET THE PARKING BRAKE AND REQUESTED THAT A TUG BE SENT OUT TO PUSH ME BACK ONTO THE TXWY. A COUNTY OFFICIAL CAME OUT AND BELIEVED THAT HE COULD MARSHAL ME BACK INTO THE CTR OF THE TXWY; BUT THE NOSEWHEEL WAS STILL NOT ABLE TO TURN. I SET THE PARKING BRAKE AGAIN AND ONCE AGAIN REQUESTED THE ASSISTANCE OF A TUG. SNOW HAD TO BE PLOWED AND SAND APPLIED BEFORE THE TUG WAS ABLE TO PULL US BACK ONTO THE TXWY. THIS WHOLE EVENT WOULD LIKELY HAVE BEEN AVOIDED HAD I HELD MY POS ON THE DE-ICE PAD UNTIL RECEIVING TAXI CLRNC AND THAT IS CERTAINLY WHAT I WILL DO FROM NOW ON. MY ONLY OTHER RECOMMENDATION IS THAT SOME THOUGHT BE GIVEN TO EXPANDING THE ARPT PAGE IN PIT TO A LARGER FOLD-OUT VERSION AS MANY OTHER LARGER ARPTS HAVE. THIS MAY HAVE ALERTED ME TO A MORE ACCURATE DEPICTION OF THE 'C' DE-ICE PAD AND ITS PROX TO TXWY B. THIS SIT RESULTED IN CLOSING THE 'C' DE-ICE PAD AS WELL AS A PORTION OF TXWY B. MY CONCERN WAS FOR THE SAFETY AND WELL BEING OF MY PAX AND CREW AS WELL AS THE ACFT.