What is a "hold short" line?

A "hold short" line is a critical safety marker on the airport's taxiway system. It is a painted line that signifies the point where vehicles and aircraft must stop before entering active runways. This line is essential for ensuring that proper separation is maintained between taxis and runway operations, thereby preventing potential collisions or incursions.

When a vehicle or aircraft approaches a runway, it must stop at the hold short line until it receives explicit clearance from air traffic control to proceed onto the runway. This procedure is vital for maintaining safety on the airfield, especially in busy operational environments where multiple aircraft and vehicles may be in motion at the same time.

The other options describe elements relevant to airport operations, but they do not specifically pertain to the hold short line. A designated parking area for aircraft, for instance, serves a different purpose entirely, as does marking for restricted areas and temporary markings for construction zones. Each of these serves important functions, but they do not encompass the safety and procedural significance of the hold short line.