A preferred route for a town’s bypass in Carmarthenshire has been announced by the Welsh Government, along with making the town’s main thoroughfare one-way only.

Discussions and consultations have taken place for years about how to address congestion and poor air quality in the town of Llandeilo, through which runs the A483 trunk road.

The bypass would start south of Llandeilo at a new roundabout, then cross the River Towy and head north alongside the railway before veering north-west and connecting to the A483-A40 roundabout north of the town. Much of it would be on an embankment to avoid flooding problems.

There would also be one-way traffic in Rhosmaen Street in the town centre – for decades a pinch-point for lorries – which the Welsh Government hopes will improve air quality and enhance the town’s commercial centre.

Consideration will also be given to opening up some existing routes for cycling and walking, priority bus use, and better connections to bus and rail links. Meanwhile, speed limits might be reduced at certain locations, such as Ysgol Bro Dinefwr in nearby Ffairfach, to improve safety.

Labour MS Julie James said the announcement followed constructive talks with Plaid Cymru’s Adam Price, MS for Carmarthen East and Dinefwr.

Mr Price said: “I’m delighted that we finally have a plan in place for this bypass. The people of Llandeilo have been clear in their desire for it and we have worked hard over the last few years to get this plan into action. The statement from the Welsh Government gives a clear commitment to seeing through this project.”

Carmarthenshire councillor Edward Thomas, who represents Llandeilo and who has long called for a bypass, said: “This sounds like good news at last. We need to look at the detail now.”

Ministers also expect to publish responses to the latest consultation about improving traffic in and around Llandeilo, along with a plan which protects the preferred route, by the end of April.

Plaid MS, Cefin Campbell, who represents Mid and West Wales, said: “This has been a long time coming, and I hope that today’s announcement signals that things will now progress at pace. The bypass will be a crucially important piece of infrastructure for the Llandeilo area, and for West Wales more widely.”