The incident occurred just before 5 p.m., right before the evening rush hour. Luckily, it did not impact the direction from Paris to the provinces – the one with the heaviest traffic in the evening – as the ventilation system continued to operate normally.
However, the closure of the tunnel in the direction of Paris immediately affected traffic flow. The closure and the mandatory detours through Saint-Cloud or earlier to reach the capital led to significant congestion on the A13, paralyzed for several kilometers before exit 4, as well as on the N 118 and the A12.
By 7 p.m., while angry taxi protests and slow-moving operations continued on the ring road, the traffic information website Sytadin still reported over 270 km of traffic jams in the Ile-de-France region. This was an “unusual” level of congestion for a Monday evening.
Initially announced to remain closed for “at least” the entire evening, a partial reopening (one lane out of three) finally took place just before 8 p.m. However, traffic remained very complicated in the area.
This is not the first time the tunnel has had to be closed for safety reasons. In October 2021, it was blocked in both directions for nearly 48 hours due to the theft of several hundred meters of cables feeding all the security systems on site. This stretch of the highway, coming from the Yvelines and Normandy, sees nearly 50,000 vehicles in each direction daily.
