I was going through the AIM (Aeronautical Information Manual) chapter 2, which talks about airport lights and markings. There are 2 types of lines that designate a vehicle roadway. One is a solid line and the other is a zipper line but I could not understand the difference between the two.
Vehicle Roadway Markings. The vehicle roadway markings are used when necessary to define a pathway for vehicle operations on or crossing areas that are also intended for aircraft. These markings consist of a white solid line to delineate each edge of the roadway and a dashed line to separate lanes within the edges of the roadway. In lieu of the solid lines, zipper markings may be used to delineate the edges of the vehicle roadway.