The City of Geneva and six surrounding communes have asked for the immediate stop of the A412 highway construction between Machilly and Thonon-les-Bains. This highway, which would cross the Chablais region in Haute-Savoie, has drawn opposition from local authorities who are concerned about its environmental and social impacts. On Wednesday, October 7, Geneva’s administrative council announced it had started a legal process to halt the construction of the Machilly-Thonon link. This action follows an appeal already filed in France against the environmental permit granted for the project. Six communes—Choulex, Presinge, Gy, Puplinge, Vandoeuvres, and Lancy—are supporting the city's stance. Administrative counselor Alfonso Gomez cited concerns about biodiversity protection, referencing the National Council for Nature Protection, which warned of major environmental impacts and inadequate compensation measures. Geneva also worries that the highway could increase car traffic, given that the Léman Express, a regional rail service, is already operating in the area. According to Le Dauphiné libéré, the move to halt the project is not unexpected and is largely symbolic. French opponents had already initiated an emergency legal procedure, which allows courts to decide whether the construction can continue while the main appeal is being reviewed. A hearing is scheduled for October 14 before the Administrative Court of Appeal in Lyon. Meanwhile, construction on the project has already begun. Work started in September after being approved by Jérôme Bonet, the prefect of Haute-Savoie. Activists are increasingly trying to block the felling of trees on the site. On Wednesday, France Nature Environnement, an environmental organization, submitted a report to the prosecutor, accusing officials of endangering activists who were stationed in trees to prevent tree cutting. The A412 highway project, originally named A400, has a long history. Initially intended to connect Annemasse to Thonon-les-Bains over 35 kilometers, the project was later reduced to a 16.5-kilometer section between Machilly and Thonon-les-Bains. It received an unfavorable opinion from an inquiry commission in 1994 but was declared a public utility in 1995. A new inquiry in 2018 led to a renewed declaration of public utility by the end of 2019. The project is a joint effort involving the state, the project owner, and the concessionaire Amedea. It involves building a 2x2 lane highway over 16.5 kilometers, crossing twelve communes in the Chablais region. The stated goal is to improve connectivity between the Chablais area, the Annemasse agglomeration, the Geneva employment region, and the A40 highway. The project is estimated to cost 315 million euros and, according to Eiffage, will be fully funded without public money. It will include a free-flow toll system to manage traffic. Despite the opposition, the opening of the highway is still expected in January 2029.