Paris ring road
Boulevard Périphérique (French pronunciation: [bulvaʁ peʁifeʁik]), sometimes called Périph', is a controlled-access dual-carriageway ring road in Paris, France. With a few exceptions (see Structure and Layout), it is situated along Paris's administrative limit.
The speed limit is 70 km/h (45 mph). Each ring generally has four traffic lanes, with no hard shoulder. At junctions, circulating traffic in the rightmost lane (separated from the other lanes at this point by a continuous white line to the left) must yield priority to entering vehicles.
When travelling at the legal speed limit, it takes around 30 minutes to complete a full circuit.
Construction of the Périphérique was begun in 1958 on the former site of the Thiers Wall (the last remaining of the city walls of Paris). Destruction of this obsolete structure in the 1920s left a clear ring of vacant land surrounding Paris, which at first was claimed by slums and squatters. In order to alleviate traffic congestion, the Boulevard was planned along this land, and completed on 25 April 1973 under the presidency of Georges Pompidou. Providing a route for a quarter of all Parisian traffic movements, it quickly became the busiest road in France. It became a victim of its own success with widespread congestion, while the dense urban area surrounding it prevents its expansion.
The Périphérique consists of two concentric carriageways: the intérieur ("inner ring") and the extérieur ("outer ring"). Vehicles travel clockwise on the inner ring and counterclockwise on the outer ring. Some stretches of the road are sometimes referred to by cardinal direction. For example, in the southern half of the highway, the "inner ring" is designated as the Périphérique Ouest ("Western Ring") as traffic flows westbound whereas the "outer ring" is designated as the Périphérique Est ("Eastern Ring") as traffic flows eastbound. In the northern half, these designations are reversed.
The structure of the Boulevard Périphérique is similar to most French autoroutes, UK and Commonwealth nation motorways, and American freeways in the following regards:
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