A close-up look at a high intensity, bi-directional LED inset light often located at the runway edge.

Runway edge lights are used to outline the edges of runways during periods of darkness or restricted visibility conditions.

For instrument runways, yellow replaces white on the last 600 metres or half the runway length, whichever is less, to form a caution zone for landings.

A similar high intensity LED light, this time located directly on, or laterally offset from, the centreline of the runway. Runway centreline lights facilitate landing under adverse visibility conditions and are spaced 15 metres (or less) apart.

When viewed from the landing threshold, the runway centreline lights are white until the last 900 metres of the runway. The white lights begin to alternate with red for the next 600 metres, and these change to continuous red lights for the last 300 metres of the runway.