Chicane

For other uses, see Chicane (disambiguation).

A chicane is an artificial feature creating extra turns in a road, used in motor racing and on city streets to slow cars to lower speeds.

Motor Racing

Ford Chicanes during the 2007 24 Hours of Le Mans at the Circuit de la Sarthe

On modern racing circuits, chicanes are usually located after long straights, making them a prime location for overtaking. They can be placed tactically by circuit designers to prevent vehicles from reaching speeds deemed to be unsafe. A prime example of this is the Tamburello chicane at Autodromo Enzo e Dino Ferrari, which was placed after Ayrton Senna's death at the original corner. At Circuit de la Sarthe, chicanes were placed alongside the 6-km Mulsanne straight in order to slow down Le Mans Prototypes, which with Group C Prototypes went to speeds as high as 400 km/h.

Some tracks, such as the Yas Marina Circuit, feature optional chicanes. Faster cars will take the chicane, but slower cars (such as amateur club racers) may avoid the chicane because they are not capable of reaching equally high speeds on the straights. Such chicanes are used at Watkins Glen International and Daytona International Speedway, where there are separate chicanes for cars and motorcycles.

Another example of this is the Tsukuba Circuit in Japan. A chicane was added after Turn 5, creating a right turn, followed immediately by a left. This chicane is used only for motorcycles. It was implemented to divert motorcycles from taking Turn 6, which is a high speed long sweeping left corner. Turn 6 was deemed to be unsafe for motorcycles, as immediately following this is a slow right hairpin corner. This means riders may still have been leaning to the left when being expected to begin braking for Turn 7.

The term is used in other types of racing, including bobsleigh and dogleg, to indicate a similar shift in the course or track.

"Mobile chicane" and "moving chicane" are terms often used to describe slower drivers and vehicles who hold other competitors up. In some cases they may not move out of the way quickly enough to allow competitors in higher positions (having completed more laps) past, despite repeated showings of blue flags. This can cost competitors valuable time and championship points. This same term, applied to traffic calming, can refer to the usage of portable devices to create a chicane configuration.

Chicanes such as those at the Yas Marina Circuit in Abu Dhabi have become a subject of debate. For example, some of Formula One's top drivers feel that the chicane after the back straight disrupts the flow of races and impedes overtaking maneuvers.^{[citation needed]}

McLaren Team Principal Martin Whitmarsh feels that placing high speed corners after straights is a better option than using chicanes.^{[citation needed]}

Traffic Calming

A chicane used as a form of traffic calming

Chicanes are a type of "horizontal deflection" used in traffic calming schemes to reduce the speed of traffic. Drivers are expected to reduce speed to negotiate the lateral displacement in the vehicle path.^[1]

There are many variations of traffic calming chicanes, but they generally fall into one of two broad categories:

• single-lane working chicanes, which consist of staggered buildouts, narrowing the road so that traffic in one direction has to give way to opposing traffic
• two-way working chicanes, which use buildouts to provide deflection, but with lanes separated by road markings or a central island.

Limited accident data for chicane schemes indicate a reduction in injury accidents (54%) and accident severity.^[2]. However, traffic calming chicanes also occasionally lead to the deaths of vulnerable road users.^[3]

See also

• Chicane (barrier)

References

1. ^ A Road Safety Good Practice Guide for Highway Authorities, First Edition, Appendix A.6, TRL Limited, Judith Barker and Chris Baguley, for the UK Department for Transport, March 2006 (Accessed 16 August 2011)
2. ^ UK Department for Transport Traffic Advisory Leaflet 12/97, December 1997 (Accessed 16 August 2011)
3. ^ Wakefield driver is cleared of causing biker deaths, 11 February 2011 (Accessed 16 August 2011)