The Lä rdal Tunnel is the longest road tunnel in the world (24.5 km). The tunnel is divided into four sections with the help of special grottoes. These grottoes serve as a turning point for cars, and are also used as a rest stop. The lighting in each grotto is also different, so that the trip does not tire the driver with its monotony. We managed to test the functionality of the tunnel within the framework of force majeure. Emergency telephones are installed along the route - they arrive at the exit within 30-40 minutes.→