The N5 Ballaghaderreen to Scramoge Road Project in Co Roscommon has been approved by Cabinet and will now proceed to the constuction phase.
Around 34km of single carriageway road is to be bult from the western end of the existing Ballaghaderreen bypass to the townland of Scramoge.
The new road will bypass the towns and villages of Frenchpark, Bellanagare, Tulsk and Strokestown.
Pedestrian and cyclist facilities will also be provided.
The estimated cost of the work is more than €200 million and it will take three years to complete.
Minister for Transport Eamon Ryan said: "The Ballaghadereen to Scramoge project will replace one of the worst sections of primary road in the country.
"By completing the missing links in the N5 corridor it will improve access to the north west.
"The new route will also make the towns and villages it serves more attractive places to live, work and shop by diverting heavy traffic, trucks and other heavy goods vehicles out of their centres".
The new road is expected to result in the removal of approximately 70% of traffic from the existing N5 corridor, improving safety, air quality and noise, and creating a more attractive route for active travel.
Minister of State for Transport Hildegarde Naughton said the scheme "will eliminate sections of the N5 that have had collision rates nearly twice above the national road average" and improve safety for all road users, including pedestrians and cyclists.
The new route is shown in red on the map below
