What does route clearance ensure for a pilot?

Route clearance is a formal authorization from air traffic control (ATC) that provides pilots with a specific flight route along with any necessary instructions regarding their departure and arrival procedures. When a pilot receives route clearance, it confirms that they are authorized to proceed with their flight as planned, according to the specified route provided by ATC.

This authorization is essential for maintaining safety and efficiency in the air traffic control system. It ensures that aircraft are sequenced properly and helps to avoid conflicts with other air traffic. When pilots receive this clearance, they can confidently follow the intended flight path that has been coordinated with ATC.

While the other answers present different aspects of flight procedures, they do not accurately capture the primary function of route clearance, which is to provide the pilot with the authority to proceed with their planned route.