What does a zipper line indicate?

A zipper line indicates where a vehicle corridor crosses an aircraft taxi lane or taxiway. This marking serves as a visual warning to both drivers of ground vehicles and aircraft that they are approaching an area where vehicles may intersect with the pathways used by aircraft.

Understanding this marking is crucial for maintaining safety in airside operations, as it helps prevent accidents by clearly delineating areas where there may be potential conflicts between vehicle and aircraft movements. The zipper line functions as a guidance tool, ensuring that drivers are aware of their surroundings and can navigate through such intersections carefully.

In contrast, the other options describe different markings or functions related to airside operations, but they don't accurately reflect the specific purpose of the zipper line. For instance, while there are designated parking spots for aircraft and stopping points before runways, these are marked differently and serve different operational purposes.