What is the primary purpose of using centerline markers?

The primary purpose of using centerline markers is to guide paint striping machines. These markers provide a visual reference that helps ensure that the paint is applied in a straight line down the center of the runway, maintaining alignment and visibility for pilots and air traffic operations. Properly aligned striping on a runway is crucial for safety as it directs aircraft during takeoff and landing.

Centerline markers are specifically designed to be functional for the paint application process, allowing workers to maximize accuracy and efficiency. While the other options mention important features of runway operation or safety, they do not relate directly to the specific guiding function provided by centerline markers for paint striping.