How do runway markings and lighting work together?
Paint is the picture by day and lights are the same picture by night. They are set out together, so a pilot reads one runway layout in every condition, with the lights adding colour and brightness control.
Runway markings and runway lights are two forms of the same visual guidance. The main runway elements (threshold, centreline, touchdown zone and edges) each have a marking and a light at the same place on the runway, so what a pilot learns from the paint in daylight carries over to the lights at night.
1One picture, two forms
The threshold, centreline, touchdown zone and edges are each shown twice: as paint, and as lights. The pilot sees the same shapes in the same places, so the runway is understood at once whatever the light.
2Lights add what paint cannot
Lights carry colour and brightness. Green marks the threshold, red the runway end, and the centreline lights change colour as the end approaches. On an instrument runway the edge lights turn yellow near the far end. The intensity is raised or lowered to suit the visibility, which paint can never do.
3Set out together
Both come from the same survey control. Centreline lights run along the marking and, where they cannot sit on it, may be offset uniformly to one side by not more than 0.6 m. Edge lights sit at the runway edge or not more than 3 m outside it. The innermost lights of each touchdown zone barrette pair match the lateral spacing of the touchdown zone marking. Inset lights are placed beside or between the paint, which is applied around them.
4Where they fall out of step
Resurfacing that moves a centreline, paint or rubber over a lens, faded markings beside bright lights, or a closure shown in only one form all break the match. After works, the markings and lights are checked together, and a closed runway gets its closed marking and has its lights switched off at the same time.
| Element | Marking | Light | How they line up |
|---|---|---|---|
| Threshold | Stripes just past the threshold | Green threshold lights | Both fix the same threshold position |
| Centreline | White dashed line | White, then red and white, then red | Lights along the line, uniform offset up to 0.6 m |
| Touchdown zone | Aiming point and paired bars | Paired white barrettes | Innermost lights match the marking spacing |
| Edges | Continuous side stripes | White, yellow near the far end of an instrument runway | Lights at the edge or up to 3 m outside |
Frequently Asked Questions
Q1Why does a runway need both markings and lights?
Markings carry the picture by day and lights carry the same picture by night and in low visibility. A runway that is read the same way in every condition lets the pilot judge position and distance without having to relearn the layout.
Q2Do the centreline lights sit on top of the marking?
They are placed along the centreline, so they sit on or beside the dashed marking. Where that is not practicable, ICAO Annex 14 allows them to be offset to one side of the marking by a small amount, up to 0.6 m, as long as the offset is uniform.
Q3Why must touchdown zone lights match the marking spacing?
The innermost lights of each pair of touchdown zone barrettes are set at the same lateral spacing as the touchdown zone marking. The pilot then sees the same width of picture in daylight and at night, which helps judge the touchdown area.
Q4What do lights show that paint cannot?
Colour and intensity control. Green threshold lights, red runway end lights, the centreline lights that change colour as the runway end nears, and yellow edge lights near the far end of an instrument runway all add information. Lights can also be dimmed or brightened to suit the visibility.
Q5What happens to the lights when a runway is resurfaced and re-marked?
The new markings are set out from the survey control, and the inset lights are re-levelled or repositioned to match. The team then checks that lights line up with the markings and that paint and sealant have not covered any lens.
Q6What should the lights show when a runway is closed?
A closed runway shows a closed marking (a white cross under ICAO; the FAA uses a yellow X), and its lights are switched off except for maintenance. Markings and lights are changed together, so a closed runway is never left lit like a usable one.
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