Runway numbers describe direction, not length

The large numbers painted on a runway do not describe its length. The US Federal Aviation Administration’s manual bases the designation on the approach direction, using magnetic heading rounded to tens of degrees.

The letters L, R and C distinguish parallel runways: left, right and centre as viewed on approach. They separate nearby runways with similar orientations.

This is an aircraft navigation reference, not a boarding-gate number. Passengers should continue to follow their airline and airport instructions.

The number visible near a runway threshold identifies its approximate magnetic orientation. As described in the FAA's aeronautical guidance, it does not represent how long the runway is or the distance available for landing. The opposite end of the same runway normally has a designation corresponding to the reverse approach direction.

At airports with parallel runways, letters such as L, C and R distinguish left, centre and right as seen on approach. This convention helps pilots and controllers identify runways unambiguously. For passengers, it is a useful way to understand airport photographs and aeronautical maps, not a substitute for gate information or an indication of flight duration.