The Frejus tunnel between France and Italy, which was closed after a fatal fire in June, is to reopen this week.
Two truck drivers died in the fire, thought to have started on a lorry carrying a load of tyres. The blaze raged for several hours, heating the inside of the tunnel to 1,200 degrees.
But French Transport Minister Dominique Perben now says the damage is not as bad as first feared.
The tunnel is the main route through the northern Alps between France and Italy and the news will be welcomed by the thousands of holidaymakers setting off on their summer holidays.
From Thursday, cars, motorbikes and trucks of less than three and a half tonnes will be allowed back.
Heavier trucks and semi-trailers will only be allowed at certain times. Dangerous loads remain banned.