DC9 EXCURSION ON TXWY AT COU.

Narrative

DURING TAXI FROM RAMP TO ACTIVE RWY ON UNCTLED ARPT; WE SELECTED A TXWY THAT WAS TOO NARROW AND HAD A WT LIMIT THAT WAS BELOW OUR ACFT WT. DURING THE TRANSITION FROM ONE TXWY TO THE OTHER (R TURN) OUR R MAIN GEAR LEFT THE TXWY AND ENTERED THE SOFT TURF. WE BECAME STUCK AND NEEDED TO BE TOWED OUT. FACTORS INVOLVED: 1) THE COMMERCIAL CHART ARPT DIAGRAM DID NOT CONTAIN ANY RESTRS ON THE USE OF THE TXWY; NOR WERE THERE ANY ARPT SIGNS RESTRICTING USE. OUR RTE PROCS MANUALS HAD THE ARPT DIAGRAM AND A NOTE RESTRICTING THE USE OF THE TXWY IN QUESTION; BUT WE DID NOT REF IT BECAUSE WE NORMALLY USE IT TO FIND PARKING INFO; FUEL VENDOR INFO; AND DEICE INFO; NONE OF WHICH WERE NEEDED. 2) THE MARSHALLER GAVE US AN INITIAL TAXI INSTRUCTION AND TO TURN TO THE R. ONCE WE STARTED OUR TURN; WE COULD PLAINLY SEE THE TXWY IN QUESTION. THIS RTE WOULD BE THE SHORTEST RTE TO OUR PLANNED DEP RWY. SINCE THERE WAS NO TWR IN OP; WE DIDN'T RECEIVE SPECIFIC TAXI INSTRUCTIONS. 3) THE ACR OPERATING CHARACTERISTICS ARE ONE OF AN EXTREME EMPHASIS ON TIME. I FEEL THAT THIS CAUSES PEOPLE (ALL EMPLOYEES) TO BE RUSHED IN THEIR JOB DUTIES. THIS CAN AND DOES LEAD TO MISSED INFO AND ERRORS. THIS; COMBINED WITH OPS ON THE 'BACK SIDE OF THE CLOCK;' CAN BECOME A SERIOUS OPERATIONAL LIABILITY.