For over 30 years, SEMAPA has been managing highly ambitious urban redevelopment projects on the left bank of the Seine in Paris. In the early 2000s, it initiated a project to redevelop the Masséna-Bruneseau sector, an area crossed by the Paris ring road and marked by a major motorway interchange. Ateliers Lion Associés came up with the idea of radically transforming this interchange, changing the way traffic flows, to make way for a new urban transparency under the ring road, recreating a link between Paris and Ivry.

Artelia implemented this project, overcoming a number of challenges: temporarily diverting one of the busiest 2×4 lane road sections in Europe, fitting a complex worksite into an extremely small space, preserving the surrounding buildings, cleaning up a former railway and industrial zone, etc. without interrupting traffic and while ensuring the safety of all concerned. To achieve this, Artelia mobilised a multi-disciplinary team bringing together all the engineering expertise and implemented both technical innovations (high studded walls for the bypass of the ring road) and organisational innovations (phasing of an extremely complex urban worksite). The site itself was subject to original environmental and nuisance control measures (evacuation of soil by barge, systematic treatment of asbestos pollution and soil, etc.).

All the commitments were met, without the slightest incident and with flawless communication to the public. This exemplary project won the Construction/Development prize in the 2019 Grand Prix national de l’ingénierie, one of France’s most prestigious engineering awards. Today, a new district has emerged that encourages soft mobility under the ring road, demonstrating that it is possible to reconcile the city with its road infrastructure.