Before the use of starting lights in Formula One and most other FIA sanctioned or associated events, the national flag of the country in which a race is occurring, instead of a green flag, was used to signal its start and still does on occasion in the event of equipment failure.The officials will utilize the cars in the field to facilitate the final drying of the course, but in order to not waste fuel (affecting fuel strategy, etc.), and delay the race further, the laps are counted towards the advertised race distance. This is sometimes called a “running yellow” and usually occurs when a track is drying after a rain delay. In NASCAR, a green and yellow flag waved at the same time indicates that the race is being started or restarted under caution and laps are being counted.A separate green flag displayed at the entrance to the pit area indicates that the pits are open.When shown at a marshaling post, a green flag may indicate the end of a local yellow-flag zone.At all times, however, the green lights remain lit.

No flag displayed at the starter’s stand implies safe, green-flag conditions. However, the flag itself is typically not continuously waved by the starter. If the race is not under caution or delayed, it is said to be under green-flag conditions. The waving of a green flag is almost universally supplemented with the illumination of green lights at various intervals around the course, particularly on ovals. During a race, it is displayed at the end of a caution period or a temporary delay to indicate that the race is restarting. The solid green flag is usually displayed by the starter to indicate the start of a race. In addition, the green, yellow, and red flags described below may be augmented or replaced by lights at various points around the circuit. Status flags are used to inform all drivers of the general status of the course during a race. Alternatively, some race tracks employ lights to supplement the primary flag at the start/finish line. Track marshals are also stationed at observation posts along the race track in order to communicate both local and course-wide conditions to drivers. Typically, the starter, sometimes the grand marshal of a race, waves the flags on top of a flag stand near the start/finish line. Racing flags are traditionally used in auto racing and similar motorsports to indicate track condition and to communicate important messages to drivers.

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