The last section of single track on the A830 Road to the Isles is scheduled to be upgraded this summer.
The road runs between Mallaig and Fort William
Morrison Construction has won the contract to work on the 4.6 mile (7.5km) stretch of the road between Fort William and Mallaig.
A protest calling for improvements to the A830 was staged in the 1990s.
Highland councillor Michael Foxley, who was involved, said the blockade was inspired by a demonstration staged by Mohawk Indians in Canada.
Transport Minister Tavish Scott said that work would begin in June and will benefit both local people and tourism.
He added: "This is an important investment for the Highlands."
Recalling the blockade at the village of Morar, Mr Foxley said: "I came back with an idea from Canada.
"The Mohawk Indians were blocking a road to draw national attention to their circumstances and we blocked the road at Morar to bring the campaign back on track."
The total cost of making 16 miles (27km) of the route a two-lane road is £22.8m.