A chicane consists in significantly deflecting the trajectory of traffic to one side. It is used both to calm speed and to improve the urban design of the surrounding landscape. Three kinds of chicane can be distinguished: on approach roads into a built-up area, next to the built-up area entrance sign, in a built-up area in zones with a 50km/h speed limit, and in built-up areas in 30km/h zones.A pinch point is a narrowing in the road designed to allow only one vehicle to pass through at a time. Traffic is allowed through in alternate directions. A pinch point involves less of a constraint on the traffic trajectory than a chicane. Traffic is slowed down mainly because vehicles travelling in one direction have to stop to allow vehicles travelling in the opposite direction to pass. There is no guide on the subject of chicanes or pinch points. A national workgroup led by Certu is working on the draft of a guide due to be published in 2009.