Plans for a £135m bypass in Gwynedd have been approved, 10 years after it was first proposed.
First Minister Carwyn Jones said the new six mile (10km) road between Caernarfon and Bontnewydd will "connect communities".
Construction could start in November and be completed by spring 2021 with a process to award a contract set to start in June.
Local councillors said the decision was a "relief" after years of delays.
Dafydd Meurig, Gwynedd council's deputy leader, said: "It has taken some time, however we can now look forward to seeing work get underway on this important project for the area, which we hope will ease traffic congestion."
Councillor Aeron Jones, of Llanwnda ward, said: "It's costing £135m now, which means the price has gone up dramatically since the bypass was first proposed.
"We've heard so many promises that some people had come to believe that it would never happen, so it's a relief in that regard."
Work on the road had been expected to begin last autumn after a public inquiry ended.
But in March the Welsh Government said it needed more time to consider the "volume of correspondence" received.
The first minister said: "The bypass will not only help connect communities in the area through sustainable and resilient infrastructure, but also provide a vital link to the A55 and beyond to Ireland, England and Europe."
Some 22 structures, including seven bridges, are planned for the project which will help ease congestion on the A487 between Plas Menai and Llanwnda.
It is expected to have two lanes in one direction and one lane in the opposite direction.