What visual marker indicates where vehicles should cross an aircraft taxi line?

The visual marker that indicates where vehicles should cross an aircraft taxi line is represented by white "zipper" lines. These lines are designed to provide clear guidance not just for vehicles but also for pilots and ground personnel. The white "zipper" lines help in demarcating the appropriate crossing areas, ensuring that the movement of vehicles is orderly and safe in proximity to active taxiways. They promote awareness and compliance with airport regulations, enhancing safety by visually guiding operators on where it is permissible to cross without interfering with aircraft operations. This is essential for preventing accidents and ensuring smooth logistics on the airside of the airport.