Wednesday 25th April 1973

Boulevard Périphérique, a ring road (French: périphérique) around Paris was completed. It is a frequently congested stretch of 8-lane dual carriageway, and is one of the busiest motorways in Europe, with traffic in excess of 1.1 million vehicles per day. Travelling speed on the road is limited to 70 km/h (45 mph). The right-hand lane is reserved for vehicles entering or preparing to leave the “normal” movement of vehicles in the other lanes, or the Boulevard itself. A solid white line separates the recently entered traffic and the circulating traffic. This is done to prevent entering traffic from disrupting the flow of circulating traffic in the inner lanes, as without the line any traffic must yield to any entering traffic across all lanes. There is no hard shoulder (emergency lane), except around the Porte de Gentilly. This means that accidents can cause considerable disruption to the traffic, and makes it difficult for emergency services to reach the scene of an accident. The full circuit of the Boulevard Périphérique measures a total of 35.04 kilometres, as measured along the central reservation. The route closely follows the municipal boundaries of Paris. It diverges in three places; in the Bois de Boulogne and the Bois de Vincennes (where the roadway is entrenched and covered), and the Heliport of Paris. Because the Boulevard was built over the old Thiers Wall, its entrance/exit ramps and interchanges coincide with the city gates, or portes in that wall. The road crosses the River Seine via bridges upstream at Charenton/Bercy and downstream at Saint-Cloud/Issy.