Which statement is true regarding controlled taxiways?

The statement indicating that controlled taxiways are managed by Air Traffic Control (ATC) and require clearance before crossing is accurate because controlled taxiways are critical areas of the airport where the movement of aircraft and vehicles must be coordinated to ensure safety.

In these areas, ATC provides instructions to vehicle operators to maintain safe distances from taxiing aircraft, which helps to prevent accidents. Clearance is necessary to ensure that the taxiway is clear and that the vehicle operator adheres to any specific instructions from ATC. This requirement underscores the importance of communication and adherence to procedures within the controlled environments of airports, where the risk of collisions is heightened due to the proximity of multiple types of aircraft and vehicles.

Contrasting this with the other options, vehicles cannot enter controlled taxiways without permission; pedestrians are generally not permitted to walk across these areas due to safety concerns; and the idea that all vehicles can use them at any time is misleading, as access is strictly regulated to maintain safety.