Tenders have been invited from consultants to work on technical and advisory services to plan the upgrade of the M4 between Maynooth and Leixlip.
The work involves the widening of the M4 from two lanes to three, in each direction.
The project is listed as a priority in the National Development Plan 2018-2027.
It involves around 10 kilometers in length.
A kilometre and a half is in South Dublin County area and the rest is in Kildare.
Labour General Election candidate, Emmet Stagg said the project went through a pre-appraisal stage which was approved by the Department of Transport last January.
He said Transport Infrastructure Ireland told him that Kildare County Council has recently invited tenders for the provision of technical advisory services to progress the planning and design work on the project.
Mr. Stagg said that the M4 at present suffers from serious congestion and the project would improve journey time reliability and improve connectivity.