AGL Visual Encyclopedia ENTRY 7 · RUNWAY LIGHTING SYSTEMS

What are Stop Bar Lights?

A row of red lights spanning the taxiway at a runway holding position, switched on by air traffic control to positively command aircraft and vehicles to stop before entering the runway.

stop bar (illuminated)

holding position marking

taxiway centreline (active)

centreline (interlocked off)

runway edge lights (context)

The Fact ICAO Annex 14

A stop bar consists of lights spaced across the taxiway at the point where it is intended that traffic shall stop, showing red in the direction of approach to that point.

Stop bars are provided at a runway holding position — typically to protect the runway during low-visibility operations — and are switched on and off by air traffic control to positively command when aircraft and vehicles must stop and when they may proceed.

Colour Red

Function Command a stop at the holding position

Location Across the taxiway, at the holding position

Spacing Uniform intervals, not more than 3 m, across the taxiway

Light type Elevated and/or inset

Operation Steady · ATC switched

Interlock With taxiway centre line lights

Reference ICAO Annex 14

Diagram is a schematic plan view of a taxiway/runway intersection only — fixture count, spacing, and the holding position marking are illustrative, not a literal layout.

Where installed, stop bar lights are interlocked with the taxiway centre line lights: when the stop bar is illuminated red, the centre line lights beyond it are extinguished (for at least 90 m), and when the stop bar is switched off to release traffic, those centre line lights illuminate in turn — a built-in check against an aircraft or vehicle proceeding on a light that was never meant to guide it past the bar.

Important Distinction

Stop bars, runway guard lights, and taxiway centreline lights are often co-located at the same holding position, but each carries a different instruction:

Taxiway Centreline Lights→ guide the aircraft along the taxiway
Runway Guard Lights→ flash yellow alternately to warn that a runway is ahead
Stop Bar Lights→ burn steady red and are switched by ATC to positively command a stop

Key Points

ICAO Stop Bar Lights

Under ICAO Annex 14, a stop bar consists of lights spaced across the taxiway at the point where traffic is intended to stop, showing red in the direction of approach to that point. Stop bars are provided at a runway holding position, typically to protect the runway during low-visibility operations, and air traffic control switches them on and off to command when aircraft and vehicles must stop and when they may proceed.

Stop Bar Light Colours

Stop bar lights show red in the direction of approach and burn steady, switched by ATC. They are not the only lights at the holding position: runway guard lights flash yellow to warn that a runway is ahead, and taxiway centreline lights guide the aircraft along the taxiway. Where installed, the centre line lights beyond an illuminated red stop bar are extinguished for at least 90 m, and they illuminate in turn when the bar is switched off to release traffic.

Stop Bar Light Spacing

Stop bar lights are spaced at uniform intervals of not more than 3 m across the width of the taxiway, at the point where traffic is intended to stop. The fixture count and spacing in the diagram are illustrative, not a literal layout, so take the exact spacing from the applicable standard and the approved design.

FAA Stop Bar Lights

This entry describes stop bars as set out in ICAO Annex 14. For an FAA-governed project, take the stop bar layout and fixture requirements from the FAA advisory circulars, such as AC 150/5340-30 for design and installation, and confirm the current edition and whether it applies to your airport.