The speed limit entered into force on Friday and will remain until further notice. It applies to all vehicles travelling in the direction of Schengen.
The authorities anticipate that re-levelling roadworks to address the issue with the road surface will be carried out at the end of September.
The speed displayed by the CITA dynamic signs will be taken into account by the average speed camera installed in the area.
The 90 km/h speed limit will still apply to traffic travelling in the other part of the tunnel towards Bettembourg.
