The more recent repairs, costing as much as the initial outlay for construction, involved installing a second, modern, fireproof layer, enabling the tunnel to meet European safety standards after St Gotthard and Mont Blanc tunnel fires, along with new air extraction systems and new lighting. Work began in March 2005 and was scheduled to last until at least April 2006, with one of the tunnels closed during off-peak hours (19:00 to 07:00 daily). However, problems that were encountered meant the work was only completed in 2010.