Get trained
This page explains the principles. It is not a substitute for instruction from a racing school or a sanctioning body's driver education program, and it does not replace the rules and tech requirements of the event you enter.
The briefing governs
Flag meanings, the flags in use and the response required differ between organizations, series and individual events. Follow the flag rules given in the drivers' briefing and the regulations of the event you enter, not this page.
This page compares three rule sets. The FIA's International Sporting Code, Appendix H (2026 edition, published 23 June 2026), sets out the FIA's flag signals. SCCA publishes its flag meanings for Time Trials, and its new-racer guidance points road racers to the flag section of its General Competition Rules (GCR 6.1). For NASCAR we used an explainer from Hendrick Motorsports (January 2026), because the NASCAR Rule Book itself was not available to us. Where a source does not describe a flag, the table says so rather than guessing.
Who shows the flags
Appendix H separates flags shown by the Clerk of the Course (the national flag, red, chequered, black, black with orange disc, and black-and-white diagonal) from flags shown at marshal posts around the track. Marshal posts wave the red flag only when the Clerk of the Course tells them to.
The three rule sets side by side
| Signal | FIA Appendix H (2026) | SCCA (Time Trials flag page) | NASCAR (per Hendrick Motorsports, 2026) |
|---|---|---|---|
| Green | Track clear. Waved at the post just after an incident. May also signal the start of a warm-up lap or practice session. | Shown only from the start/finish station. Course clear, competition under way. | Not described in our source. |
| Yellow, first level | Single waved yellow: hazard beside or partly on the track. Visibly slow, no overtaking, be ready to change direction. | Standing (motionless) yellow: danger beside the track. Slow significantly, pass the incident at reduced speed, no passing until past it. | Yellow (caution): the field slows for an incident or debris and a pace car takes control of the pack. |
| Yellow, second level | Double waved yellow: hazard wholly or partly blocking the track and/or marshals working on or beside it. Slow significantly, no overtaking, be ready to change direction or stop. In practice or qualifying, abandon the lap. | Waving yellow: very dangerous incident that may partly or fully block the track. Slow significantly, be ready to stop, single file where possible, no passing. | Not described in our source. |
| Whole course neutralised | Safety Car: "SC" board. Virtual Safety Car or Full Course Yellow: single yellow plus a "VSC" or "FCY" board. Code 60: purple flag with "60", a 60 km/h limit around the whole course. | Race Services Inc., which says it follows SCCA flagging guidelines, uses two motionless yellows at every station as a full course yellow, called only by the Operating Steward. | The caution brings the field behind the pace car. |
| Yellow with red vertical stripes | Held motionless: reduced grip from oil or water. Shown for at least four laps (depending on circumstances) unless the surface recovers first. | Shown standing for slippery conditions or debris. May be withdrawn once everyone has seen it, even if the hazard remains. | Not described in our source. |
| Blue | Light blue, waved: you are about to be overtaken. In practice a faster car is close behind; in a race, a car about to be lapped should let it pass. Held still at pit exit: traffic approaching. | Solid blue, or blue with a yellow or orange diagonal stripe. Standing: a close follower may want to pass, so consider letting them by. Waving: a fast car is approaching or held up, so let it by as soon as it is safe. | Blue with a yellow stripe: lead-lap cars are approaching slower cars. |
| White | A much slower vehicle in that post's sector. | Shown standing two stations before a slow car, ambulance or emergency vehicle. May also be shown on each group's first lap of the day to mark station locations. | One lap to go. If a caution comes out while it is shown, the field is frozen and the race ends. |
| Red | Waved at the start line and every post. Slow down and go to the red-flag line (or the pits in practice). No overtaking; pit exit closed. | Extreme danger, session stopped. Make a controlled stop at the side of the track, preferably near a staffed station, and go to pit lane only when an official releases you. | All on-track activity stops, and teams may not work on cars in the pits or garage. |
| Black with car number | Shown motionless with the number: stop at the pit or designated place at the next pit approach. Not shown for more than four consecutive laps if ignored. | Open black with number: go directly to the pits or designated place to see officials, without another lap. Open black at all stations ("black flag all"): session stopped, all cars return to the pits with extreme caution, and those laps do not count. | Black with crossed white lines: shown when a driver has ignored a black flag for five laps; the car is no longer scored. |
| Mechanical problem | Black with a 40 cm orange disc: the car has a problem likely to endanger the driver or others. Stop at the pit next lap; rejoin only once the chief scrutineer is satisfied. | Black with an orange or red ball ("meatball") and number board: go to the pits without another lap. | Not described in our source. |
| Warning | Black and white, divided diagonally: shown once only, as a warning for unsportsmanlike behaviour or an action that may be penalised if repeated. | Furled (rolled) black flag pointed at the car: warning for unsafe or improper driving. Continuing leads to an open black flag. | Not described in our source. |
| Chequered | Ends the session or race. Waved until all competing cars have crossed the Control Line. | Not described on the Time Trials flag page. The 2026 SCCA Track Day Rules make it mandatory at every event. | Shown mid-race to mark the end of a stage. RACER instead describes a green-and-white chequered flag for stage ends, so sources differ. |
The differences that catch people out
- White. FIA: a much slower vehicle on track. SCCA: shown two stations before a slow or emergency vehicle. NASCAR and much US oval racing: one lap to go. A driver who switches between series has to relearn this one.
- Two levels of yellow, named differently. The FIA distinguishes single waved from double waved yellows. SCCA distinguishes standing (motionless) from waving yellows. RACER notes that some series treat a waved yellow as more urgent than a stationary one.
- Double yellow. Under Appendix H, a double waved yellow at a post covers a blocked track near that post. In SCCA-style US club flagging, Race Services Inc. uses two motionless yellows at all stations to signal a full course yellow.
- Blue. The FIA flag is light blue. SCCA's may be solid or carry a yellow or orange diagonal stripe. NASCAR uses blue with a yellow stripe. Race Services Inc. says the striped blue is used more in practice and qualifying than in races, and a 2019 NASA Speed News article on HPDE calls the striped flag the passing flag.
- Warnings. The FIA uses the black-and-white diagonal flag, shown once. SCCA uses a furled black flag pointed at the car.
- Red. FIA drivers continue slowly to the red-flag line, or to the pits in practice. SCCA drivers stop at the side of the track near a station and wait to be released. Race Services Inc. also says red-flag stops should be within sight of a flag station.
- The surface flag. Appendix H says it is shown for at least four laps unless the surface recovers. Race Services Inc. says it is usually shown for up to two laps and never waved, and SCCA says it may be withdrawn once everyone has seen it. These are different organizations' practices, not a contradiction within one rulebook.
- Black flag and other cars. Race Services Inc. notes that passing is still allowed while a black flag is being displayed to a car.
Which flags an event uses
Not every event uses the full set. SCCA notes that some events use only yellow, black and chequered flags (plus blue where passing is allowed), and some use lights instead of flags; the event's Supplemental Regulations say which. The 2026 SCCA Track Day Rules make yellow, black and chequered flags mandatory at every track day, with blue also mandatory where passing is allowed, and say flags must be obeyed immediately and without question. A 2019 NASA Speed News article on HPDE passing likewise says rules given at the drivers' meeting override its general guidance.
Lights and boards
Appendix H allows light panels to supplement waved red, yellow, green, blue and white flags if an event's Supplementary Regulations say so. They must be visible at 250 m in bright sunshine and flash at 3 to 4 Hz. Red lights are controlled only from race control, and yellow lights are mandatory at every post for night racing. Posts should also carry an "SC" board (black letters on white) and an "FCY" board (black letters on yellow).
At an FIA standing start, red lights on the gantry mean stay stationary and prepare, and the lights going out means start. Flashing yellow lights mean stay stationary and switch engines off. For a rolling start, the red lights shown during the formation lap are replaced by green to start the race.
Appendix H also sets minimum flag sizes of 60 by 80 cm, with red and chequered flags at least 80 by 100 cm, and gives Pantone references for each colour (for example red 186C and light blue 298C).
What we left out
We did not include a NASCAR pit-road-closed flag or NASCAR overtime procedures, because each came from a single secondary source we could not confirm. We also could not read the current SCCA GCR or NASA CCR flag sections directly. For how flags fit into a session, see the race weekend, and for passing etiquette at track days, see track days.
Sources
- FIA, International Sporting Code Appendix H (2026, PDF)
- FIA, regulations: International Sporting Code and appendices
- SCCA Time Trials, flags
- Race Services Inc., flag descriptions (PDF)
- SCCA Track Day Rules (updated 23 December 2025, PDF)
- Hendrick Motorsports, NASCAR flags and their meanings (January 2026)
- RACER, what do the different colored flags mean
- SCCA, advice for drivers new to SCCA road racing (2026, PDF)
- NASA Speed News, passing in HPDE 1 and 2 (2019)