The Sallins By Pass, and the new junction on the M7, open on Friday.
These are the final two elements of a €110 million up-grade, which has seen the construction of the Osberstown Interchange and the widening to three lanes of the motorway from the ball at Naas.
Kildare Garda Division says the by-pass at Junction 9A will be operational from 11am on Friday.
These routes will provide improved access to Naas, Sallins, Clane & Kilcock and provide relief on existing local routes.
The new Sallins Link Road from the By Pass will remain temporarily closed to facilitate ongoing works at Millbank, Sallins
Image: road schematic/Kildare Garda Division