What are intermediate holding-position lights?

Where provided, intermediate holding-position lights consist of three fixed, unidirectional yellow lights, arranged symmetrically about — and at right angles to — the taxiway centre line at an intermediate holding position. An intermediate holding position is a designated position on a taxiway, usually at an intersection or crossing with another taxiway, where air traffic control may require an aircraft or vehicle to stop and hold until cleared. It is not a runway-holding position. The lights are spaced 1.5 m apart and sit 0.3 m before the intermediate holding position marking. Where a stop bar is installed at the position, it is used instead of these lights. On a taxiway intended for use in RVR below 350 m, Annex 14 requires intermediate holding position lights at an intermediate holding position unless a stop bar has been installed there.

The unidirectional design is deliberate: the lights are built to be seen only by an aircraft approaching the holding position from the taxiway side, so they read as a clear stop cue to the crew that needs it, without adding visual clutter for traffic already past the point or travelling the other way. This distinguishes them from a clearance bar, which increases the conspicuity of an intersection generally rather than signalling one specific holding point, and from in-pavement lighting at a runway-holding position, which is a red stop bar, often with yellow flashing runway guard lights.