What is the significance of the letters L and R in runway identification?

The letters L and R in runway identification signify "left" and "right," which are essential for pilots navigating in a controlled airspace with parallel runways. When an airport has multiple runways designated for the same orientation—such as two parallel runways oriented north-south—the designations ensure clarity and safety in communication. This differentiation helps pilots understand which runway they should use for takeoff or landing, reducing the likelihood of confusion and potential accidents.

For example, if an aircraft is instructed to land on the left runway, the use of L clearly indicates which specific runway to approach, even when other similar runways are present. This system promotes efficient operations at busy airports and maintains situational awareness for both pilots and air traffic control.