A86 autoroute

It follows an irregular path around Paris with the distance from the city centre (Notre Dame) varying in the 8–16 kilometres (5.0–9.9 mi) range.

The south-western section of A86 contains one of the world's longest urban motorway tunnels (10 km (6.2 mi) of continuous tunnel) known as the Duplex A86 [fr], opened in two parts in 2009 and 2011.

The tunnel is limited to a height of 2.0 m (6 ft 7 in) and commercial vehicles are prohibited as a result.

Although now a complete motorway-standard loop, the A86 is a product of its heavily urban route and piecemeal construction, meaning that there are several points at which one has to turn off to stay on (TOTSO) and sections which are briefly parts of the A3 and A4 autoroutes.

[1] A86 is a part of the five-ring-road system surrounding Paris and Île-de-France: The Duplex A86 is a 10 km (6,2 mi) long motorway tunnel in Paris, which forms part of the A86.

Overview of Paris ring roads. The outer Grand contournement de Paris compared with Francilienne (green), A86 (blue) and Boulevard Périphérique (orange).
Inside of the 10 km (6,2 mi) Duplex A86 [ fr ] Tunnel northbound. The hard shoulder is on the left because the fire exits are located on the left side, as shown in this picture. The reverse is true when going southbound.