Different coloured flags are in use from early days of motoracing to communicate with drivers about different conditions on the track, penalty situations and start and end of the race. All marshals at different points around the circuit are issued some of this standard flags to communicate this messages to drivers.
Same is with F1 racing. But F1 will not be F1 if there is not something highly technological involved. Special display on steering wheel, with differently colored lights in colour of the flag lights up when driver pass the affected sector of the track. This system is known as GPS marshalling system. System is invented and introduced because at such high speed or because of the conditions on the track, driver sometimes can't see marshal's flag. Signal to GPS marshalling system lights is send to car from race control.
Indicate start or end of the race. In F1 case, only end of the race. Also indicate end of practice and qualifying session. On the end of the race it is shown first to the winner and then to every car that crosses the line after him. About starting procedure in Formula 1 check here.
Danger on the track ahead of the given signal. A single waved yellow flag warns drivers to slow down. Drivers should reduce their speed and be prepared to change direction. It must be clear that a driver has reduced speed and, in order for this to be clear, a driver would be expected to have braked earlier and/or reduced speed in the relevant marshalling sector. During yellow flag period, overtaking is prohibited, unless it is clear that a car is slowing with a completely obvious problem.
Double waved Yelow flag
Danger on the track ahead of the given signal. Any driver passing through a double waved yellow marshalling sector must reduce speed significantly and be prepared to change direction or stop. In order for the stewards to be satisfied that any such driver has complied with these requirements it must be clear that he has not attempted to set a meaningful lap time, for practical purposes this means the driver should abandon the fast lap. During yellow flag period, overtaking is prohibited, unless it is clear that a car is slowing with a completely obvious problem.
All clear, you can continou with race
Stop of the session.
Indicate that driver that hi is about to be lapped. Driver must left faster car to overtake him. If he doesn't comply, after 3 blue flags hi risk to be penalized.
Yellow and red striped flag
Slippery track surface, usually because of oil or water.
Black with orange circle flag
Shown together with a car number, it warns a driver that he has a mechanical problem and must return to his pit.
Half black, half white flag
Shown together with a car number, it warns a driver of unsporting behavior. May be followed by a black flag if the driver does not comply with the warning.
Shown together with a car number, it order a driver to return to his pit. Most often is used to signal to the driver that he has been excluded from the race.
Warns racing drivers of a slow moving car on track. Can be ambulance or firefighters.
But as we all know, F1 is moving forward every day.
Close observers of the Formula One's winter 2008 testing at Barcelona may have noticed the conspicuous absence of marshals waving caution flags when something goes wrong.
That's because F1 tried its latest innovation in the name of driver safety, the electronic flag.
Placed visibly in the braking zones, these large displays are able to change to all the applicable F1 flag colors, and are said to be much easier to see than a marshal waving from the sidelines. The FIA has considered the electronic flags for a while, liking the notion of the race director being able to have control over deploying the flags from a central location.
What is more, with these electric warning signs hooked up to a standard control unit, teams will be able to easily integrate this software into their exsisting GPS Marshaling software allready in their cars.
Most often displayed flag is yellow flag, indicating danger on the track ahead of the first flag given on the track. During yellow flag period drivers must proceed with caution and overtaking is strictly forbidden in a yellow zone - indicated by yellow flags waved by trackside marshals, flashing trackside yellow lights and by an indicator on their car's steering wheel (GPS marshalling system). Rules dictate that the 'yellow' zone (or danger period) ends only when the driver passes the first 'green' indicator. If a driver is caught overtaking in a yellow-flag zone, the punishment is either "drive through" penalty, or 20 seconds added to a driver's race time if the incident takes place close to the end of the race or is investigated after the race.
Just to clear few things. If there is any discrepancy between what is displayed on a driver's dashboard and what is being displayed on the track, then the trackside flags and lights take precedence. If there is any discrepancy between trackside light and flags, the first signal is what counts - whether it is a light or a flag. So if, for example, a yellow flag is displayed followed later by a yellow light, then no overtaking area begins at the first yellow signal which would be the flag.
Added to that if, after yellow flag period, a green flag is waved before a green trackside light board is displayed, it is the first green that counts, ag. when there are consecutive signals from both a flag and a light, it is the first one that counts.
NASCAR racing, for example have some differences from Formula 1 flag signals. In addition to individual flag signals, flagman can use combination of roled flags. Flagman is the person standing on the tower above the Start/Finish line who controls the race with a series of flags.
- by crossing two rolled-up flags into an "X" shape - the halfway point of the race; usually shown with the white & green flags
- by crossing the black and white flag - that scoring has been discontinued for your car
- by holding his hand out with wilth all five fingers spread wide apart - "5 Laps To Go"
- by showing the white & green flags rolled up and held next to each other, in a upwards position (straight up) - that there is "2 Laps To Go"
- by displaying the yellow & checkered - there has been an accident in the back of the field, the race is over BUT be careful because the track is blocked ahead.
The Flags of NASCAR Racing
Green: Start Or Restart - Course Is Clear
All races start with a green flag. The green flag is also displayed on restarts during an event.
Yellow: Caution - Slow down and Hold your Position
Signals the drivers to slow down because of a problem on the track, including accidents, debris, fluids on the track or some other hazard. drivers are required to slow down, exercise caution and maintain their relative position. Cars may not pass (advance a position) under the yellow flag but the balance of the field may close up behind the leader.
Black: Pull Into Pits
No driver likes to see the black flag, which is given to send a driver to the pits for either a problem with the car (oil leak, for example) or another infraction such as improperly lining up on a restart or rough driving. This flag will be shown TWICE. If a driver does not comply, he will be disqualified from the race.
Red: Stop - Bad Wreck - Course Blocked
If the situation warrants a total stoppage of the race, such as rain, the flagman will display the red flag, which tells the drivers and crews that the race is being halted due to some unsafe condition.
Blue/Yellow Diagonal Stripe: Move Over - Use Another Lane
The most commonly used flag during a race, which is known as the move-over flag. This flag is given to a car that is being overtaken by lead-lap cars and asks them to give the leaders the courtesy of moving over.
White: One Lap To Go
Indicates to the driver that they have started their last lap. During road coarse events, the white flag may also be used by corner workers to indicate that an emergency vehicle is on the racetrack.
Indicates the completion of the race.
8.9 Track signal information display :
All cars must be fitted with red, blue and yellow cockpit lights the purpose of which are to give drivers information concerning track signals or conditions. The lights must be LEDs each with a minimum diameter of 5mm and fitted directly in the driver's normal line of sight. Details of the light control system, which must be fitted to every car, may be found in the Appendix to these regulations.
148. Duties of road observers and flag marshals
The track or road marshals shall occupy, along the course, posts assigned to them by the stewards of the meeting or the organising committee. As soon as a meeting begins, each track or road marshal is under the orders of the clerk of the course to whom they shall immediately report by any means at their disposal (telephone, signals, courier etc.) all incidents or accidents which might occur along the section for which they are responsible.
Flag marshals are specifically entrusted with flag signalling (see Appendix H). They may also be track or road marshals.
At the end of each competition, all track or road marshals must give the clerk of the course a written report on the incidents or accidents recorded by them.
During competitions, and unless otherwise instructed by the clerk of the course, track or road marshals shall, as far as possible, inform the central bureau of information concerning the order in which competitors have passed their post. This shall be effected lap by lap in the case of a closed circuit.