Final answer:
Establishing new instrument/radar approaches or making changes to existing instrument/radar approaches may require temporarily closing a runway or taxiway via NOTAM.
Step-by-step explanation:
Establishing new instrument/radar approaches or making changes to existing instrument/radar approaches may require closing a runway or taxiway temporarily via NOTAM (Notice to Airmen).
NOTAMs are used to communicate important information to pilots and other aviation personnel about temporary changes or hazards at an airport or within a specific airspace.
By issuing a NOTAM to close a runway or taxiway, air traffic control ensures the safety of aircraft during these changes and allows for the implementation or modification of instrument and radar approaches.