Achicane (/ʃɪˈkeɪn/) is aserpentine curve in a road, added by design rather than dictated by geography. Chicanes add extra turns and are used both inmotor racing and on roads and streets toslow traffic for safety. For example, one form of chicane is a short, shallow S-shaped turn that requires the driver to turn slightly left and then slightly right to continue on the road, requiring the driver to reduce speed. The wordchicane is derived from theFrench verbchicaner, which means "to create difficulties" or "to dispute pointlessly", "quibble", which is also the root of theEnglishnounchicanery.[1] The Spanish verbchicanear also means "to use trickery".[2]
On modern racing circuits, chicanes are usually located after long straights. Due to being preceded by heavy braking zones, they are regularly used as overtaking spots. They can be placed tactically by circuit designers to prevent vehicles from reaching speeds deemed to be unsafe. Examples of this include: three chicanes at theAutodromo Nazionale Monza, introduced in the early 1970s; the Chase atMount Panorama, added in 1987; and the Tamburello chicane atImola, which was placed in 1995 afterAyrton Senna's death at the original corner. AtLe Mans in 1990, two chicanes were placed on the 6 kilometres (3.7 mi)Mulsanne Straight whereGroup Cprototypes had previously achieved speeds of 400 kilometres per hour (250 mph) in order to conform to new international regulations limiting the maximum length of a straight on a motor racing circuit to 2 kilometres (1.2 mi). Chicanes can makeslipstreaming less potent.[3] The term is used in other types of racing, such asbobsleigh, to indicate a similar shift in the course or track.
A slower driver or vehicle that delays competitors is sometimes disparaged as amobile chicane ormoving chicane. 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 ofblue flags. This can cost competitors valuable time and championship points.
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.[4] There are several variations of traffic-calming chicanes, but they generally fall into one of two broad categories:
Limited crash-data for chicane schemes indicate changes in injury crashes (range from −54% to +32%) and crash severity.[clarification needed][5][6]
Chicanes can also be used to prevent access to certain vehicles. TheVermont Agency of Transportation has considered adding chicanes toRoute 108 inStowe andCambridge to prevent the passage oftractor-trailers, which often get stuck further up the road.[7]
Apedestrian chicane is a kind of permanentfence used at arailway crossing to slow pedestrians down and to force them to observe both directions before crossing therailway tracks. While passing the chicane, one has to turn to the left and to the right, increasing the probability of seeing an approaching train. A similar arrangement is sometimes used at the entrances ofparks to impedebicycle, car, mobility scooter, and wheelchair access.
