According to the operator ATMB, the closure will begin on Monday 1 September at 5 p.m. and remain in place until Friday 12 December at 5 p.m. During this period, the Mont Blanc Tunnel will be entirely shut to traffic — for both freight and passenger vehicles.
The renovation works are so extensive that a full closure is unavoidable. Given the tunnel’s strategic role in trade between France and Italy, the shutdown presents significant logistical challenges for international road transport.
Alternatives: limited and problematic
ATMB has published a map of alternative routes, but each option comes with drawbacks:
- The Fréjus Tunnel is the most obvious alternative, but heavy congestion is anticipated. Hauliers are advised to monitor traffic reports closely.
- The Great St Bernard Tunnel (on the Swiss-Italian border) offers another route, but it has restrictions: ADR transport is not permitted (class E tunnel).
Other mountain passes may be used, but their availability depends on weather conditions, making them particularly risky in autumn and winter.
