When is a flashing red light on the ground used?

A flashing red light on the ground is used to indicate that aircraft should taxi clear of the runway in use. This signal is commonly found at airports to alert pilots that there is some kind of hazard or that the runway is active. It provides critical information for maintaining safety on the airport surface by directing pilots to vacate the runway and thus prevent potential collisions or other dangerous situations.

In contrast, other signals have different meanings, such as being cleared to land, exercising extreme caution, or returning for landing, which are distinct and have specific indications tied to them. Understanding these signals helps pilots navigate airport operations safely and efficiently, ensuring that they respond appropriately to ground control instructions.