Money will pay for improvement to 2.5km section along the A40.
Deputy First Minister Ieuan Wyn Jones has announced a £19 million boost from the EU Convergence funding for a major transport route through West Wales.
The new cash will help pay for improvement of a 2.5km section along the A40 from Penblewin to Slebech Park, including a bypass for the Pembrokeshire village of Robeston Wathen.
The bypass will provide additional overtaking opportunities helping to improve journey times and reduce traffic noise for local residents. A 2+1 overtaking layout means that the central lane of the three-lane road becomes an alternating overtaking lane controlled by road marking.
This latest funding will form part of an overall £37 million investment already committed by the Welsh Assembly Government to improve journey times and road safety along the route, which serves as a vital link with West Wales, Ireland, the UK motorway, the trunk road network and Europe.
The scheme will also help develop around 1km of additional footpaths linking with existing public paths and bridleways via two underpasses either side of Canaston Bridge.
Jones said: "Work on the new bypass will enhance the existing transport infrastructure, improving safety and journey time reliability along the A40."
"It will help improve quality of life for people living in the village of Robeston Wathen and deliver access to jobs and services along this important east/west corridor in South West Wales."
Welsh Assembly Government