Motorists are being warned of heavy traffic expected from tomorrow afternoon and across Thursday as many people head off for the Ascension Day weekend.
The routes heading to Italy are likely to be most affected, including the Mont Blanc tunnel. Police warn waiting times may last for hours.
Special traffic controls are being put in place around the tunnel. Authorities in Haute Savoie are calling on drivers to make sure they listen to traffic reports and try to avoid the busiest periods – which will start midday tomorrow and last until Thursday at 3pm.