Final answer:
A 'Controlled Taxiway' is a designated taxiway at an airport under the control of ATC that requires a D AVOP for access and mandatory ATC clearance.
Step-by-step explanation:
A taxiway under the control of Air Traffic Control (ATC) that requires vehicles to have a D AVOP (Airside Vehicle Operator’s Permit) and mandatory clearance from ATC before entry or crossing is known as a Controlled Taxiway. These areas are critical for the safety and management of airport operations. Access to a Controlled Taxiway is restricted to ensure that the movement of aircraft and vehicles does not interfere with airport operations and maintains safety protocols established by the aviation authorities.