What determines the classification of a taxiway at an airport?

The classification of a taxiway at an airport is primarily determined by control by air traffic control. This is because air traffic control plays a crucial role in managing the movement of aircraft on the airfield, ensuring safety and efficiency in operations. Taxiways are categorized based on the level of control required for operations, which can include considerations like the volume of traffic, proximity to runways, and the necessity for clearance to operate in certain areas.

Different classifications indicate how and when aircraft can use the taxiway, with some needing greater oversight than others due to traffic patterns or operational requirements. This classification helps in ensuring safe navigation for aircraft as they taxi between the runway and terminal, or to other areas of the airport.

The other factors, such as height restrictions for vehicles, type of aircraft using the taxiway, and length of the taxiway, do have importance in the overall management and safety of airport operations, but they do not define the classification system of the taxiways in the same primary manner that air traffic control does.