Yellow Flag

A yellow flag in motorsport is a warning signal displayed to drivers indicating there is a hazard on or near the racing track, requiring them to slow down immediately and prohibiting overtaking until the danger has passed.

When drivers see a yellow flag, they must reduce their speed and stay alert. The flag tells them something dangerous is ahead—this could be a crashed car, debris on the track, a vehicle that has stopped in an unsafe location, or track workers (called marshals) who are on or near the racing surface dealing with an incident. The most important rule is simple: no passing other cars while the yellow flag is being shown.

The way a yellow flag is displayed tells drivers how serious the danger is. A single yellow flag held still means there's a hazard near the track but not directly on the racing line where cars drive. A single yellow flag being waved back and forth indicates a more serious situation—the hazard is on the racing surface itself, and drivers need to be ready to change direction quickly. When two yellow flags are waved at the same time, this signals the most serious situation: a major hazard is blocking the track, or marshals are working directly on the racing surface, and drivers must slow down significantly and be prepared to stop completely if needed.

Different racing series handle yellow flag situations in slightly different ways. In some championships like IndyCar, a yellow flag shown at one marshal station creates a "local yellow" affecting only that section of track, while twin yellow flags at the start/finish line mean the entire track is under caution and a pace car will come out to control the speed of all cars. In Formula 1, yellow flags are displayed at marshal posts around the circuit to warn drivers about hazards in the next section of track ahead.

Some racing series use what's called a "Full Course Yellow" or FCY. During these periods, all drivers must slow down to a specific speed limit—for example, 80 kilometers per hour in the FIA World Endurance Championship or 50 kilometers per hour in Formula E. Drivers must also maintain a safe distance from the cars around them, and overtaking remains strictly forbidden. Formula E cars even have a special speed limiter button that drivers press to automatically control their speed during these caution periods.

The yellow flag zone ends when drivers pass a green flag, which signals that the track is clear and normal racing can resume. At this point, drivers can accelerate back to racing speed and overtaking is permitted again.

Breaking yellow flag rules carries serious penalties because ignoring these warnings puts drivers, track workers, and other personnel in danger. If a driver passes another car under yellow flags or fails to slow down appropriately, they can receive penalties ranging from time added to their race result to a stop-and-go penalty where they must enter the pit lane, stop for a specified time, and then rejoin the race. Ignoring double waved yellow flags—the most serious warning—can result in a 10-second stop-and-go penalty or even disqualification from the race.

Yellow flags work alongside other warning flags to keep everyone safe. For instance, a yellow and red striped flag warns of a slippery surface ahead from oil or water, while a white flag indicates a slow-moving vehicle like a safety car is on track. Understanding and respecting yellow flag signals is fundamental to safe racing in all forms of motorsport.