Sensor inputs command the in-pavement lights to illuminate red when there is traffic on or approaching the runway. Runway entrance lights (REL), one status-light component, are located on entrance ...

RWSL systems consist of two types of lights—Runway Entrance Lights (REL) and Takeoff Hold Lights (THL). They function automatically and are independent of air traffic control. RELs are installed ...

The lights tell pilots when a runway is clear ... There are other indicators, however, alerting pilots of the runway entrance and where to stop short, like the red and white "16R-34L" runway signage ...

Weather alert system, runway lights weren't working at San Diego airport as plane approached before crash, officials say.