A £10m project to widen a stretch of road in Ceredigion is to start next month after a 20-year campaign.
Work on 1.3km (0.8 mile) of the A487 at Glandyfi near Machynlleth is expected to be completed in late 2012.
Two major rock cuttings will widen the road that is so narrow in parts oncoming vehicles can only just pass.
Meanwhile, tributes have been paid to the late Machynlleth councillor, Bill Evans, who worked "tirelessly" for the road improvements.
Mr Evans, who died in 2007 after 28 years as a town councillor, wrote dozens of letters to UK and Wales government officials during a 20-year campaign for improvements at Glandyfi.
Fellow Machynlleth councillor Michael Williams said: "Bill fought really hard for these improvements. He worked tirelessly.
"The road is so narrow there that is causes major congestion problems in the tourist season and if two lorries meet on the road then there can been lengthy tailbacks.
"The work will be a lasting legacy to Bill's wonderful work. I am sure his perseverance over that lengthy period of time played an important and significant part in the work finally going ahead."
Transport Minister Ieuan Wyn Jones said the investment by the Welsh Assembly Government would improve traffic flow.
"The main aim of this improvement is to allow vehicles to pass freely and reduce delays on this section of road," he said.
"The accident rate, a result of the narrow width on this section of road, is higher than the national rate for this category of road, so the improvements are necessary to enhance safety."
He said every effort would be made to keep delays to a minimum while the work was carried out.