Île-de-France traffic: freeways and roads closed in August

August 2025 promises to be a difficult month for road traffic in the Paris region. The Direction des Routes d'Île-de-France (DiRIF) plans to take advantage of this off-peak period to carry out a series of works. The result? Major roadworks have been announced in the Île-de-France region, leading to the closure of several major routes, including the A6a and Route nationale 406. We take stock.

While some Parisians love summer in Paris, others dread this period, which is often synonymous with roadworks. In addition to work on public transport, renovation work is also planned on the roads and freeways of the Ile-de-France region. That's what the Direction des routes d'Île-de-France (DiRIF) has announced.

So beware, dear motorists, traffic is going to be difficult this August 2025 in the Île-de-France region. A series of roadworks will result in the closure of several major routes, including the A6a and the 406.

As the DiRIF points out in a press release, the summer period"allows work to be carried out more efficiently: weather conditions are more favorable and traffic is at its lowest in the height of summer compared with the rest of the year". In June, July and August, it is thus possible"to reduce the number of lanes open to traffic, or even to close an axis continuously, with much less significant impact on travel times", explains the Île-de-France Roads Authority, which states that it invests"nearly 200 million euros each year to maintain its network, which comprises some 1,100 km of freeways and trunk roads, 25 tunnels and 1,950 engineering structures (bridges, viaducts, retaining walls, etc.)".

What are the consequences? More and more road closures and roadworks during the summer. So you'll need to be patient and find alternatives for driving in the Paris region in August, as several major routes will be completely closed.

This is the case on the RN104. In detail, pavement renovation work will require the RN104 to be closed 24 hours a day over a 14 km stretch between Pontault-Combault and Évry-Grégy-sur-Yerres (77). The N104 will be closed in the inland direction (A4 to A6) from Monday August 4 at 9:00 pm to Thursday August 14, 2025 at 1:00 pm. Then, from Monday August 18 at 9:00 pm to Thursday August 28, 2025 at 10:00 pm, the N104 will be closed in the outbound direction (A6 to A4).

The RN406 between Boissy-Saint-Léger and Créteil will also be closed. From Monday August 4 at 6am to Friday August 8, 2025 at 6am, the RN406 will be closed in the province > Paris direction (between Boissy-Saint-Léger and Créteil). Then, from Monday August 18 at 6am to Thursday August 21, 2025 at 6am, the same RN406 will be closed, this time in the Paris > province direction (between Créteil and Boissy-Saint-Léger).

On the RN14,"pavement safety work" has led to the 24-hour closure of this trunk road. It will be closed until Friday August 22, 2025 at 5:30pm, in both directions, in the commune of Puiseux-Pontoise (95) over a distance of around 1.5 km.

Another route, another project. Since July 17, until September 4, traffic has been on one lane on part of the A6b. As indicated on the Sytadin website, the slow lane of the A6b, in the Paris-province direction (Tunnel d'Italie),"is neutralized from the Boulevard Périphérique to the Bicêtre tunnel". The access ramp to the A6b, in the Paris-province direction from the D126B departmental road, is closed for the duration of the works.

Another disruption to be expected on Paris region roads in August 2025? Due to rehabilitation work on the major viaduct of the N118/A86 at Vélizy-Villacoublay (78), the N118 slip road, in the Paris-Provence direction towards the A86 towards Créteil, is completely closed until Friday August 8 , 2025 at 5:30 am.

And the summer roadworks don't stop there. Pavement renovation work on the RN12 will entail"a change of carriageway" from Monday August 4 at 9:00 pm to Thursday August 28, 2025 at 5:00 am at Guyancourt (78). Traffic will thus be on a single lane in each direction in the work zone.

There will also be traffic restrictions on the A6a in the province-to-Paris direction. Until Thursday August 14, 2025,"pavement renovation, drainage and restraint system work on the A6a will be carried out along a 200 mstretch in the province-Paris direction". Then, from Thursday August 14 to Monday September 8, 2025, repair work on the Arcueil viaduct will require lane reductions 24 hours a day. "Traffic will be on a single lane in the Province-Paris direction, and two lanes in the Paris-Province direction", says DiRIF.

So remember to study your route carefully beforehand and consult the alternative itineraries suggested on the Sytadin application or website.