Beneficiary rule

The 2009 NASCAR rule change brings it in line with Grand-Am road racing, while rules where lapped cars between leaders may gain one lap were adopted in Formula One as of 2007. The lapped-car rule in Formula One applies when the "lapped cars may overtake" signal appears on team monitors from race control.

See also:

Porsche 911 GT3

The American version of the 997 GT3 RS has a standard rear window (not plexiglas) and the smaller 911 fuel tank to comply with rules of SCCA, Grand-Am, and IMSA. For Grand-Am races, the central locking wheel nut is replaced with the standard five-lug pattern required under Grand-Am rules.

In the IndyCar Series, lapped cars ahead of the leader following pit stops (which may happen if a lapped car does not pit during yellow when the lead lap cars do so) are allowed to move to the tail end of the lead lap on restarts on the one lap to go signal—which automatically closes the pit lane until the restart.

This ensures that the leaders take the green flag without interference from lapped traffic. NASCAR follows the same policy with the 2009 change to the Beneficiary Rule, except that pit lane is only closed to those cars that were waved around the safety car to allow the leaders to start at the front.

According to Jayski.com, seven drivers have won a race being the beneficiary in NASCAR Sprint Cup alone, with two drivers doing it twice.

Most beneficiaries accumulated in a race:

NOTE: Kyle Busch was the beneficiary in five consecutive caution periods at the 2006 AMD at the Glen; the beneficiary rule was not used on road course events in 2004. The first driver not on the lead lap—no matter how many laps they are behind the leader—gains one lap back per beneficiary; another reason the rule is somewhat unpopular.

In Busch's case, he lost five laps from repairs caused by an oil leak, and upon returning to the track, gained all five laps back through the beneficiary rule because no other driver was between him and the lead lap on any of the caution periods.

(Source: Wikipedia)