Fleurieux-sur-l'Arbresle. Collapsed road on the RD307: investigations are underway

The reconstruction of a collapsed roadway is one of the upcoming major projects to be carried out by the Department. President Christophe Guilloteau and Vice-President for Roads Patrice Verchère made a field visit on July 8 to the RD307 (formerly RN7), which has been added to the departmental road network .

"Studies have begun to find the origin of a road subsidence. Observed locally for several years, it has been developing unfavorably since last year. Initial investigations have made it possible to characterize the nature of the soils and carry out a diagnosis of the existing situation through road cores and pressuremeter tests carried out to a depth of 3 meters. The diagnosis carried out shows instability of the existing soils and heterogeneous layers present at depth," the Department explained in a press release. The presence of layers of roadway likely originating from old roadways before the site's redevelopment has been identified.

Based on the results of the studies, the Department is considering three reinforcement solutions. "Reconstruction of the roadway only; rockfill or the installation of a nailed Berlin wall before reconstruction of the roadway," the authority specifies.

Investigations are ongoing until March 2026. The choice of a reinforcement solution will be made in June 2026. "Depending on the recommended technique, the work could be carried out in the summer of 2026 or, if the reinforcement technique is more complex, by the spring of 2027," the press release concludes.