What is clearance delivery's main role at an airport?

Clearance delivery's primary function at an airport is to provide pilots with the initial departure clearance and relevant instructions while their aircraft is still on the ground. This includes issuing flight plans, standard routing, and information about any necessary regulatory requirements before takeoff. This role is crucial as it helps ensure that aircraft are in compliance with air traffic control procedures before they begin to move, enhancing both safety and efficiency in airport operations.

The other options, while they pertain to other important aspects of airport operations, do not correctly describe the specific duties of clearance delivery. Instead, landing instructions, taxiway traffic management, and weather updates are handled by ground control and tower control, respectively. Thus, providing initial departure information while the aircraft is still parked accurately reflects the main role of clearance delivery at the airport.