Runway Edge Lights vs Taxiway Edge Lights: ICAO Annex 14 Color Coding Guide

Under low visibility or night operations, airport surface movements rely heavily on Aeronautical Ground Lighting (AGL). The color difference between runway edge lights (white/yellow) and taxiway edge lights (blue) is not arbitrary. It is a calculated engineering choice standardized under ICAO Annex 14 to balance luminous intensity, atmospheric penetration, and safety redundancy.

1. Runway Edge Lights: The "Green-White-Yellow-Red" Closed Loop

Runway edge lighting provides a high-intensity, color-tiered reference line for pilots during high-speed take-offs and landings.

• Runway Threshold (Green): Marks the start of the operational runway. It signals "clear to land" to approaching aircraft.
• Main Runway Section (Aeronautical White): Delivers the highest lumens and maximum penetration. It allows long-distance alignment at high speeds.
• Last 600 Meters (Aeronautical Yellow): Mandated by ICAO Annex 14 Section 5.3. This segment alerts pilots of braking margins and the imminent end of the runway.
• Runway End (Red): Defines the absolute physical endpoint. It serves as an impassable visual red line to prevent runway overruns.

Engineering Highlights (Model: HLPD-2A Elevated LED)

• Dual-LED Backup: Features primary/secondary chip relay. Single-source lifespan exceeds 8,000 hours.
• Wind Resistance: Withstands wind loads up to 560 km/h with 6.6A 5-stage constant current dimming.
• Frangible Base: Uses a frangible coupling at the base. It shears cleanly upon impact to protect aircraft structures.

2. Taxiway Edge Lights: Boundary Isolation and Incursion Prevention

Once an aircraft exits the runway, speed drops. Visual guidance shifts from long-range penetration to precise boundary identification at lower speeds.

• Aeronautical Blue Light: Blue has a shorter wavelength and high contrast for low-speed taxiing. It rarely appears elsewhere in airport lighting, creating an unambiguous physical boundary to prevent runway incursions.
• Curvature Densification: Spacing drops from a maximum of 60m on straights to 7.5–15m at curves and intersections. Combined with 360° omnidirectional output, it ensures boundary visibility at any steering angle.

Note: For Cat II/III operations, pilots use green centerline lights for primary guidance, while blue edge lights define the physical pavement limits.

Engineering Highlights (Model: SGZ-2A Elevated LED)

• IP66 Protection: Die-cast aluminum body with O-ring seals resists salt spray, high humidity, and heavy rain.
• Eco-Friendly Efficiency: Delivers a 50,000+ hour lifespan. It cuts energy use by 80% compared to halogen fixtures, maximizing airport ROI.

Technical Specification Comparison: HLPD-2A vs SGZ-2A

Summary

Runway lighting solves high-speed distance anticipation and critical warnings. Taxiway lighting handles low-speed boundary definition and incursion prevention. Striking compliance with ICAO Annex 14 is the baseline for airport safety, and selecting highly reliable, long-life hardware is the key to maximizing long-term airport operational returns.

To request technical datasheets or project quotations for HLPD-2A and SGZ-2A, please contact us.