A public consultation has been launched on plans for the upgrade of the road between Strabane and Newbuildings.
The A5 Western Transport Corridor is one of five key transport projects in Northern Ireland and the proposed work will improve links between urban centres in the west of Northern Ireland.
Transport Minister Michelle McIlveen said construction of the £150 million road should start next year.
She said: “This important project will not only have positive benefits for the local economy and construction industry but will also significantly improve safety and journey times for all road users.”
Once the consultation period has concluded, a decision will be made on the need for a public inquiry on the scheme, currently tentatively programmed for this autumn.
At this stage, the section south of the A4 at Ballygawley to the border will not be progressed as there is no certainty from the Irish Government on funding.
The minister also said she was seeking accelerated passage for the Land Acquisition and Compensation Bill which would bring compensation levels for landowners in Northern Ireland affected by compulsory land purchase on a par with England and Wales.
She said: “Yesterday I received Executive agreement on the introduction of the Bill. I would be hopeful that the Bill will complete its legislative process during this current mandate.”