At this day the motorway network contains a dozen tunnels varying in length from hundred meters to three kilometers. The longest tunnels are Grouft with 2,6 km, Gousselerbierg with 2,6 km and Stafelter with 1,8 km on the North Motorway and Markusberg with 1,5 km on the Saar Motorway.
The tunnels are operated by the National Road Administration. Information relating to the design, construction, operation and maintenance of the tunnels can be found under the following link: https://travaux.public.lu/fr/actualites/evenements/2011/ausstellung-NEAT-tunnelbau-luxemburg.html
In the event of a closure of a motorway section, a traffic diversion plan (PGT) helps the coordination between stakeholders involved in the traffic management and the information of the road users. The coordination of the maintenance and emergency service interventions are organized according to operational plans. (PIP/PINP/PIU and PGT - Tunnels/CGDIS).