The official opening yesterday of the €204 million Ennis bypass is expected to remove 20,000 cars from the streets of Ennis each day.
Clare county engineer Tom Carey said the 14km scheme "will allow Ennis to breathe again".
Under the previous development plan, the scheme was initially due for completion in 2004 but was delayed due to inadequate funding and a requirement to redesign it to comply with new contractual requirements.
The work included the construction of a bat-house, visible from the road, which cost in excess of €100,000 to protect the lesser horseshoe bat along the route. The road's construction forms another part of the Atlantic corridor. Work on the next section, the Gort-Crusheen bypass, is due to commence next year.
Speaking after officially opening the scheme yesterday, Minister for Transport Martin Cullen described Ennis "as a key county town that provides access to many scenic and major tourist areas in the midwest region including Kilkee, Lahinch and the unique Karst limestone region of the Burren".
He said: "With its proximity to Shannon airport, Ennis facilitates many visitors from both the US and Europe and today's opening will further benefit tourism to the town, the surrounding areas and many other towns in the counties of Clare, Limerick and north Tipperary which form part of the Limerick Shannon gateway."
President of the Ennis Chamber of Commerce John Madden said: "Today is a milestone in the history of Ennis. At long last the bypass is here and we have to build on it."
According to the chairman of the National Roads Authority (NRA), Peter Malone, "schemes such as the Ennis bypass are important not just in a local context but nationally also. The bypass forms part of the Atlantic corridor, which is a core element of the Government's Transport 21 Plan.
"It will run from Donegal to Waterford and the ongoing development of this corridor will facilitate business expansion and tourism in the southeast, west and northwest of Ireland."
