How a runway and taxiway relate
A runway never works alone. Taxiways carry aircraft on and off it, and the lighting colours show the pilot which surface they are on.
Aircraft reach the runway from the apron along taxiways. A parallel taxiway runs alongside the runway at a set separation, and link taxiways join the two. Landing aircraft leave by an exit, and a rapid exit taxiway meets the runway at an acute angle so they can clear it at higher speed.
Where a taxiway meets the runway, the runway holding position marks where aircraft must stop. The AGL system supports it: green taxiway centreline lights guide aircraft to the runway, and a red stop bar holds them short of it. Lead-off centreline lights start at the runway centreline and curve onto the exit. On a runway exit they alternate green and yellow out to the edge of the ILS critical and sensitive area (or the inner transitional surface, whichever is farther from the runway), and are green beyond it, so the pilot knows the aircraft has not yet cleared that area.
Frequently Asked Questions
Q1What is the relationship between a runway and a taxiway?
A runway is where aircraft take off and land. Taxiways connect it to the apron and other areas. A parallel taxiway runs alongside the runway, and link or exit taxiways join the two.
Q2How far apart are a runway and its parallel taxiway?
ICAO Annex 14 sets a minimum separation between the runway centreline and the parallel taxiway centreline. It depends on the runway code number, whether the runway is instrument or non-instrument, and the aircraft wingspan code letter.
Q3What is a rapid exit taxiway?
A taxiway that leaves the runway at an acute angle, recommended between 25 and 45 degrees with 30 degrees preferred, so landing aircraft can slow and clear the runway at higher speed.
Q4How does the lighting tell a pilot which surface they are on?
Runway edge lights are white and taxiway edge lights are blue. Taxiway centreline lights are green, alternating green and yellow on a runway exit as far as the edge of the ILS critical and sensitive area. A red stop bar and yellow holding position marking show where taxiing aircraft must stop short of the runway.
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