The N12 in the Yvelines is undergoing a new phase of closure this week. From Monday, December 8 to Friday, December 12, 2025, the road will be closed to traffic traveling from the provinces to Paris between Méré and Plaisir, starting at 3 p.m. each day. Motorists will be able to resume their journey the next morning at 6 a.m. These disruptions are part of the Chennevières tunnel works, which have been ongoing for several weeks now.
This new stage in the modernization of the Chennevières tunnel is the latest in a long series of closures that have been affecting users' daily lives since All Saints' Day. The work has clearly accelerated since November, requiring increasingly frequent closures on this strategic route. Four times a month, extended closures take place in the area, forcing motorists to adapt their routes and plan their journeys in advance.
Since the beginning of November, the Chennevières tunnel has already undergone several phases of closure. On four occasions, the infrastructure was closed in both directions between 10 p.m. and 5 a.m. for four consecutive days. These operations took place during the weeks of November 3, November 10, November 24, and December 1, 2025. The third week of November saw a different configuration with a nighttime closure in one direction for two days, then in the other direction.
The closure announced for this week is unusual in terms of its timing: it will begin in the middle of the afternoon at 3 p.m., which is likely to further complicate traffic for motorists returning home from work. This is a notable change from previous closures, which generally took place in the evening or at night.
Motorists should be prepared for further disruption in the coming weeks. Immediately after this week's closure, the Île-de-France road authority (DiRIF) has scheduled a new phase of work. From December 15 to 18, 2025, just before the Christmas holidays, the road will be closed to traffic in both directions between 10 p.m. and 5 a.m. This is a particularly challenging period with the approach of the end-of-year holidays.
January 2026 is also set to be a difficult month for users of the N12. No fewer than four phases of work are planned. The tunnel will be closed in both directions between 10 p.m. and 5 a.m. during three periods: January 5 to 8, January 12 to 15, and January 26 to 29. Meanwhile, from January 19 to 22, the road will be closed in the Paris-province direction from 10 p.m. to noon, a daytime closure that will have a particular impact on traffic.
In view of these recurring disruptions, it is best to plan your journeys in advance and consider alternative routes. Motorists who usually use this route to get to and from work will need to make different arrangements, especially during closures starting at 3 p.m. Regularly checking traffic information on Sytadin, the DiRIF's real-time information service, and planning early or delayed departures can help avoid traffic jams on detour routes. Although disruptive, these modernization works are intended to improve long-term traffic safety and comfort for all users of the N12 in the Yvelines.
Dates and Opening Time
From December 8, 2025 to December 12, 2025
Location
Yvelines
yvelines
