A project first discussed more than a decade ago to improve traffic flow out of Monaco towards Cap-d’Ail has taken another step forward, with technical surveys now set to determine whether construction can proceed…
As reported by Monaco-Matin, Cap-d’Ail Mayor Xavier Beck has authorised the Nice Côte d’Azur Metropolis to carry out surveys for the proposed underpass on the Moyenne Corniche. The studies are expected to take place during the autumn school holidays, including work during both the day and night.
First discussed in 2013 and approved in 2022, the project would create an underground road for traffic travelling uphill from the Rainier III tunnel towards Nice. It also includes widening the roundabout near the Princess Grace Hospital and Boulevard du Jardin Exotique.
However, Beck remains opposed to the scheme, arguing that it will not resolve congestion caused by commuter traffic and could create further disruption during the proposed 18-month construction period.
Two appeals brought by Cap-d’Ail against the project were rejected by the Nice Administrative Court in January 2026. The mayor has consequently agreed to cooperate with the surveys, although he believes existing stormwater and wastewater infrastructure could present a significant obstacle.
The underpass is estimated to cost €11 million, with Monaco contributing €8.8 million. Separate road-widening works are expected to cost €20.5 million, of which the Principality would provide €15.5 million.