ACR MLG UNAUTHORIZED TAXI AT LGA.

Narrative

NORMAL LNDG ON RWY 22 LGA. CLRED AT DELTA TAXIWAY FACING NE ON OUTER TAXIWAY; CALLED GND ON 121.7. ACFT WAS STOPPED. AFTER THIRD CALL TO GND A MALE VOICE SAID; 'ACFT IDENT USE THE INNER TO THE GATE'. LGA WAS DEPARTING ON RWY 13 AND ACFT WERE TAXIING ON THE OUTER AND 'G' TO CROSS 22 TO GET TO 13. I SAW AN ACFT COME AROUND THE CORNER ON THE OUTER AND IT LOOKED LIKE WE WOULD BE NOSE TO NOSE SO I USED DELTA TAXIWAY TO THE INNER RAMP. AS SOON AS WE GOT ON THE INNER RAMP A FEMALE VOICE SAID; 'ACFT IDENT MAKE A L TURN AND RETURN TO THE OUTER; THAT IS A VEHICLE LANE'. WE COULD NOT TURN L BECAUSE THERE WAS NO ACCESS (TAXIWAY) AT THAT POINT. SHE KEPT INSISTING THAT WE TURN L UNTIL WE MADE HER UNDERSTAND THAT THERE WAS NO ACCESS TO THE OUTER EXCEPT BY DOING A 180 DEG TURN AND GOING OUT ON 'D' OR STRAIGHT AHEAD TO 'E' WHERE THE 'INNER' OFFICIALLY BEGINS. THE AREA WHERE WE TAXIED IS ALL PAVED RAMP AREA AND THERE ARE ACFT PARKED THERE AT TIMES. THERE WERE WHITE LINES DEPICTING VEHICULAR LANES RUNNING PARALLEL TO THE EDGE OF THE TAXIWAY. I AM NOT SURE THAT WE DID ANYTHING WRONG EXCEPT THAT APPARENTLY THE INNER DOES NOT START OFFICIALLY UNTIL TAXIWAY ECHO. THE CTLR SHOULD HAVE SAID; 'ACFT IDENT TRANSITION TO THE INNER AT ECHO TO THE RAMP'.