Safety improvements to the RD 909A and RD 16 district roads
As part of efforts to improve and make the road network safer, the Departmental Council will, from 14 September, carry out emergency safety works to protect against natural hazards on the RD 909A and RD 16.
Roadworks on the RD 909A in Talloires-Montmin
The RD 909A, situated in the municipality of Talloires-Montmin and exposed to natural hazards, is the subject of a safety programme led by the Haute-Savoie Departmental Council.
As part of the creation of the Lake Annecy greenway and following the initial assessments carried out, temporary protective measures in the form of mesh barriers have been installed along the crest of the road embankment. The first phase of works was completed in September 2025, involving the installation of approximately 340 linear metres of rockfall barriers.
A second phase of works will begin in September 2026. This will involve the installation of approximately 1,100 linear metres of rockfall barriers, ranging in height from 2.5 to 5 metres, supplemented by clearance, blasting and stabilisation operations designed to deal with boulders likely to exceed the protective capacity of the structures. Tree felling work will also be carried out on the hillside.
These operations, which will result in a temporary increase in the risk of rockfalls, require the complete closure of the RD 909A and the Lake Annecy cycle path for the duration of the works.
Key points
Traffic will therefore be completely suspended 24 hours a day, 7 days a week from 14 September to 18 December 2026, subject to weather conditions.
Roadworks on the RD 16 in Alex
The RD 16, situated in the municipality of Alex and at significant risk of rockfalls, is the subject of a multi-year safety programme led by the Haute-Savoie Departmental Council.
Following geotechnical investigations carried out in October 2025, two rock masses of approximately 6 m³ posing a significant risk were identified and dealt with as a matter of urgency to ensure the safety of road users.
To optimise costs and minimise disruption, the safety programme is organised by sector according to a multi-year phasing plan. It includes rock clearance operations, stabilisation works, and the installation of rockfall barriers and deflector nets.
A first phase of large-scale works will begin in September 2026. This will involve the installation of approximately 120 linear metres of 4-metre-high rockfall barriers, positioned at the top of the cliff. The works will also include the installation of nearly 1,470 linear metres of rock stabilisation anchors to secure 55 rock compartments, ranging in volume from 1 to 40 m³.
Key points
Given the site’s location, directly above the RD 16, and the risk of rockfalls caused by the works, traffic will therefore be completely suspended 24 hours a day, 7 days a week from 14 September 2026, for an estimated period of 12 weeks, subject to weather conditions.