Definition
A row of three steady, in-pavement yellow lights installed at taxiway holding positions to indicate the location of a hold point. At low-visibility taxi routes operating under SMGCS procedures, clearance bar lights also serve to denote a holding position when used in conjunction with stop bar lights and runway guard lights.
Plain English
Three yellow lights set into the taxiway surface that mark the spot where you must stop and hold until you are cleared to continue.
Context Anchor
Pilots encounter clearance bar lights while taxiing on airport movement areas, especially on low-visibility taxi routes and near places where aircraft may need to hold or watch for crossing traffic.
Derivation
Called a 'bar' because the three lights form a short line across the taxiway, and 'clearance' because crossing them requires a clearance from ATC.
Why Pilots Care
They reduce runway incursion risk by giving pilots an unmistakable visual stop point on the surface.
Intuition Check
Do not read “clearance” here as an air traffic control instruction. Clearance bar lights do not give permission to move; they only mark a location that requires attention.
Example Sentence 1
The captain stopped short of the clearance bar lights and waited for the controller to issue the next taxi instruction.
Example Sentence 2
At night the clearance bar lights clearly outlined the hold position on the taxiway.