What action is indicated by a steady red light from ATCT?

A steady red light from Air Traffic Control Tower (ATCT) is a signal indicating that vehicles and aircraft must stop. This signal is crucial for maintaining safety on the airport premises, ensuring that no movement occurs while the taxiways or runways may be obstructed or unsafe for transit.

Understanding the function of a steady red light is essential for drivers operating within the airport environment. It communicates to all personnel the need to halt their progress and await further instructions or clearance. In high-traffic areas such as O'Hare Airport, adhering to this signal helps prevent accidents and ensures coordination with air traffic controllers.

The other options pertain to different commands or situations. Returning to a starting point or preparing for landing would involve different signals or conditions, and being cleared for takeoff would be indicated by a completely different light signal, typically a green one.