Rapid Exit Taxiway Centreline Light

A Rapid Exit Taxiway Centreline Light is a specialized centreline lighting system designed for high-speed taxiway exits that guides aircraft from the runway onto rapid exit taxiways at safe speeds. These lights feature a distinctive alternating pattern (green and yellow or closely spaced green lights) that alerts pilots to an upcoming rapid exit point. The lights are typically flush-mounted (inset) in the pavement and are arranged along the centreline of the rapid exit taxiway, starting from the runway edge and extending onto the taxiway.

A rapid exit taxiway lets an aircraft leave the runway at a shallow angle without slowing to the crawl a standard 90° exit would require, which shortens runway occupancy time and increases the airport's landing capacity — but only if the pilot can find and track the exit path confidently at that higher speed. The alternating green/yellow (or closely spaced green) pattern exists specifically to give advance notice that a rapid exit is approaching, so the pilot can begin the turn smoothly rather than reacting late and overrunning or oversteering the exit.

Because this decision happens while the aircraft is still moving at meaningful speed, the lighting has to do more than mark a path — it has to communicate urgency and direction well before the geometry of the exit itself becomes visible, which is why the colour change stands out from ordinary green centreline lighting used elsewhere on the taxiway.

Rapid exit taxiway centreline lights are installed on precision approach runways at busy airports where efficient runway clearance is critical. They are used on:

• Precision approach runways (CAT II and III) with high traffic volumes
• Major international airports where runway capacity is a constraint
• Rapid exit taxiway intersections where high-speed exits are provided
• Runways with multiple rapid exit points for efficient aircraft flow
• Low visibility operations where clear guidance is essential

Fixtures follow the RET centreline's spiral/curve geometry from the runway centreline, through the turnoff curve, to the taxiway centreline, using the standard inset base can recessed into the pavement at each survey point along the curve. Spacing tightens through the curve compared with straight taxiway centreline spacing, so more fixtures and base cans are required per metre through the turn than on the following straight taxiway. Cabling follows the curved alignment in duct beneath the pavement back to the isolating transformers and on to the RET's own lighting circuit (kept separate from the parent runway and taxiway circuits so exit-light colour changes can be switched independently); setting-out is tied to the RET geometric design survey rather than a simple centreline offset.

Rapid exit taxiway centreline lights operate as an integrated guidance system:

• Identification: A series of lights (typically green and yellow alternating, or closely spaced green lights) are installed on the runway and taxiway to identify the rapid exit point.
• Indication: The distinctive pattern provides a clear visual cue to the pilot that a rapid exit taxiway is approaching, typically starting approximately 300-500 metres before the exit point.
• Guidance: The lights guide the pilot along the centreline of the rapid exit taxiway, ensuring a smooth and safe high-speed exit.
• Integration: The system is integrated with lead-off lights, runway guard lights, and other AGL systems.

An RET's control loop is kept electrically independent of both the parent runway edge/centreline circuit and the general taxiway circuit, fed from its own CCR (or its own switchable section of the ALCMS) so the exit lighting can be turned on or off as a single unit without touching runway or taxiway lighting elsewhere. Within that loop, the alternating green/yellow pattern is not something the control system switches in real time — each fixture position is wired and lensed for its assigned colour when the circuit is built, so illuminating the loop simply lights every fixture at once in its pre-set colour rather than requiring per-fixture colour selection logic. The CCR still regulates brightness across the whole loop in the usual current steps, and because the loop follows the RET's curved geometry rather than a straight run, spacing (and therefore the number of transformers and fixtures per loop) is tighter through the turn than on the straight taxiway sections either side of it.

Rapid exit taxiway centreline lights are built as flush (inset) fixtures — FAA Type L-852B (≥1200 m RVR) or L-852D (<1200 m RVR) for curved, wide-beam sections — housed in an L-868 base can set into a cored or cast recess in the pavement, with the load-bearing top surface rated to carry the full wheel loading of the heaviest aircraft using the taxiway. The lens assembly, typically dual-colour to display green and yellow segments from a single fixture body, is a hardened glass or high-strength polycarbonate unit gasket-sealed to the housing to achieve an IP67/IP68 rating against fuel spillage, de-icing fluid, and standing water. Internally, separate LED clusters or filtered lamp segments behind the green and yellow apertures are wired to the isolating transformer in the same base can, with L-823 connectors sealed against moisture at the cable entry. Because these fixtures sit directly in the path of high-speed nose and main gear wheel loads at the exit turn, the base can and surrounding pavement interface are engineered to resist shear and impact fatigue, and the fixture top is kept low-profile and chamfered to minimise tyre scrubbing damage. Stainless-steel fasteners and corrosion-resistant internal wiring are used throughout given the fixture's continuous exposure to aircraft traffic and surface contaminants.