What is the primary role of runway signs in an airport?

Runway signs play a crucial role in guiding pilots and ensuring safe operations on the airport surface. The primary function of these signs is to provide directional information to pilots as they navigate runways and taxiways. This information includes critical data such as runway identifiers, taxiway names, and other important locations on the airport layout.

By clearly displaying this information, runway signs help reduce the likelihood of runway incursions and taxiing errors, which are essential for maintaining safety in the airport environment. The signs are designed to be easily readable from the cockpit, especially during critical phases of flight, such as taxiing and takeoff.

The other options do not align with the fundamental purpose of runway signs. Altitude changes, weather conditions, and fuel prices pertain to different aspects of aviation, which are typically managed through other means such as altimeters, weather reporting stations, and fuel service providers, rather than through visual signage on the airport surface.