What is the runway edge light caution zone?
The final stretch of white runway edge lights that switches to yellow, warning an aircraft rolling toward that end that it is running out of runway.
Runway edge lights are normally white along their full length. Where the runway is long enough, the colour changes to yellow over the final stretch nearest a runway end — a visual cue that tells an aircraft rolling toward that end that it is running out of usable runway.
In ICAO Annex 14 the caution zone covers 600 m, or one-third of the runway length, whichever is less, measured back from the runway end. The FAA uses 2,000 ft, or half the runway length, whichever is less, on instrument runways. Because the zone is measured from the end, a runway used in both directions shows yellow near each end, as seen by an aircraft running toward it. On a short runway the zone is still only a fraction of the length, so a white section always remains. ICAO Annex 14 (5.3.9.7) words the zone as the section at the end remote from where the take-off run starts, and treats it as an option (“may show yellow”) rather than a requirement; the FAA applies it in the direction of use. IFALPA’s January 2025 position paper argues the yellow section should apply in the landing direction as well, citing IATA data in which 31 of 40 runway excursions (2019–2024) occurred on landing. Where the zone is provided, one row of two-colour fixtures can serve both directions: yellow toward the nearer runway end, white the other way. Follow the rule your State applies.
Frequently Asked Questions
Q1What is the runway edge light caution zone?
The final stretch of runway edge lights, normally white, that switches to yellow to warn a pilot rolling toward that end that the runway is running out.
Q2How long is the caution zone?
In ICAO Annex 14, 600 m or one-third of the runway length, whichever is less, measured back from the runway end. The FAA uses 2,000 ft or half the runway length, whichever is less, on instrument runways.
Q3Does every runway show a caution zone?
Not necessarily. The zone is only a fraction of the runway, so the rest stays white, and a runway used in both directions shows yellow near each end. Whether it is provided depends on the standard, the type of runway and the operation, so check the aerodrome's lighting design.
Q4Which lights does the caution zone apply to?
Runway edge lights only. It cautions an aircraft rolling toward that end about the runway length remaining. ICAO words it around the take-off run; the FAA applies it in the direction of use, and IFALPA (2025) recommends the same for landings.
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