The A7 motorway towards northern Luxembourg reopened on Wednesday morning after being closed for around three hours following reports of smoke in the Grouft tunnel, causing major traffic disruption during the morning rush hour. According to the Grand Ducal Fire and Rescue Corps (CGDIS), smoke was reported in the tunnel at around 5.15am, prompting authorities to close the A7 from the Waldhaff interchange from 5.20am.
Traffic backed up in several directions, with congestion stretching onto the A1 motorway and the N11 towards Eich and Gonderange.
Both the Grouft and Stafelter tunnels reopened to traffic heading north at 8.19am, allowing traffic to gradually return to normal. However, shortly before 10am, authorities announced that the motorway had to be closed once again.
By noon, authorities decided to open it back up again.
Initially, information pointed to one of the tunnel's recently replaced ventilation fans potentially having triggered the incident. Maintenance work has been taking place overnight in recent weeks to repair and replace ventilation fans in the Grouft tunnel after technical defects were identified.
However, Ralph Di Marco of Luxembourg's Road Administration (Ponts et Chaussées) denied reports that a faulty ventilation fan had caused the smoke: "At this stage, we believe that dust accumulated on the pavement between January and now, while the left-hand lane was closed. This morning, traffic must have stirred up the dust, which was mistaken for smoke."
He explained that crews from the Road Infrastructure and Traffic Management Centre (CIEA) had thoroughly cleaned the left-hand lane overnight, but the cleaning had apparently not been sufficient because there was simply too much accumulated dust.
The left-hand lane reopened to traffic on Wednesday after being closed for several months. As a result, both northbound lanes in the Grouft tunnel are now open again and the speed limit has returned to 90km/h from the temporary limit of 70km/h.
In the direction of Luxembourg City, however, one lane remains closed and the speed limit continues to be restricted to 70 km/h.
