The Taoiseach will officially open the €140 million road upgrade of the N4 between Collooney and Castlebaldwin this afternoon.
Micheál Martin will unveil a plaque dedicated to the memory of all those who died on the stretch of road.
Sligo County Council and Transport Infrastructure Ireland have estimated that the new dual carriageway will save 27 lives and result in 1,000 fewer injuries over the next 30 years.
A lack of safe overtaking opportunities, poor visibility and alignment and up to 18 junctions per kilometre, were among the factors believed responsible for multiple collisions.
The 2½-year scheme included the construction of 12 bridges and the acquisition of 200 hectares of land.
It is one of the first National Roads Projects delivered under Project Ireland 2040’s regional connectivity objective.
Meanwhile, the Taoiseach will also officially turn the sod on the construction of the N5 Ballaghaderreen to Scramogue Road Project this afternoon.