Circuit de la Sarthe
The Circuit de la Sarthe, located near Le Mans, France, is a non-permanent track most famous for hosting the annual 24 Hours of Le Mans auto race. The track uses local roads that remain open to the public most of the year. The circuit, in its present configuration, is 13.650 km (8.482 mi) long, making it one of the longest circuits in the world. Over the years, several purpose built sections have replaced the normal roads, especially in 1972, when the Porsche Curves section bypassed the dangerous former Maison Blanche section between buildings. Since 1965, a smaller but permanent Bugatti Circuit was added which shares the pit lane facilities and the first corner (including the famous Dunlop bridge) with the longer version.
Drivers frequently refer to Le Mans as a race where up to 85% of the time (including pitstops) is spent on full throttle, meaning immense stress on engine and drivetrain components. However, the times spent reaching maximum speed also mean tremendous wear on the brakes and suspension as cars must slow from over 200 mph to around 65 for the end of Mulsanne in a short distance. Downforce in the era of Group C cars helped braking to some degree but presently cars are tending towards low downforce to seek higher speeds in the face of power limiting regulations.
The track has undergone many modifications over the years. It was most famous for its 5-km (3-mi) long straight, known locally as Ligne Droite des Hunaudières or in English as the Mulsanne Straight, a part of the Route Nationale 138 road. Speeds on the Mulsanne Straight reached over 400 km/h (250 mph) and, as could be expected, it was not entirely safe. Two chicanes on the Mulsanne Straight were consequently put in place before the 1990 race to lower top speeds.
Near the end of this straight past the Mulsanne Kink was an infamous hump, which gave flight to a Mercedes-Benz CLR in 1999 during warm-ups. The same problem had occurred on the straightway between the Mulsanne and Indianapolis corners for another CLR during practice and the race. The hump was lowered during the winter before the 2001 race, again in the interest of safety. Although the hump remains, it is greatly diminished from what it was.
A new set of sweeping esses, the S du Tertre Rouge, was introduced past the Dunlop Bridge for 2002. Also, in 2006, the Dunlop Chicane was reprofiled at the request of the FIM to allow for more runoff. This modification also saw the change of the pit exit to the first apex of the chicane, which caused some controversy before the start of the 2006 Le Mans 24 Hours. Essentially, the pit exit was moved to the very end of the front straight.