Taxiway-edge markings are used to define the edge of the taxiway. They are primarily used when the taxiway edge does not correspond with the edge of the pavement. There are two types of markings, depending upon whether the aircraft is supposed to cross the taxiway edge. Continuous markings, which consist of a continuous double yellow line, with each line at least 6 in (15 cm) in width spaced 6 in (15 cm) apart, are used to define the taxiway edge from the shoulder or some other abutting paved surface not intended for use by aircraft. Dashed markings are used when there is an operational need to define the edge of a taxiway or taxi lane on a paved surface where the adjoining pavement to the taxiway edge is intended for use by aircraft, (e.g., an apron). Dashed taxiway-edge markings consist of a broken double yellow line, with each line at least 6 in (15 cm) in width, spaced 6 in (15 cm) apart (edge to edge). These lines are 15 ft (4.5 m) in length with 25-ft (7.5 m) gaps.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved