The proposed third crossing over the Menai Strait could be designed, built and opened within 4 years, according to the Welsh Government.

Plans for the new crossing are now being deigned with the aim of reducing traffic congestion on the two existing bridges. The design of the new bridge would ‘respect the old ones’ but ‘have its own character‘ according to the contactore responsible for the design.

The Welsh Government has said the new bridge could be built in two years and be open as soon as 2021. It previously said construction of a third crossing to Anglesey would only start in 2021, if it gets the go-ahead.

BBC Radio Cymru’s Manylu programme has been given details of the assessment, with the preferred route west of the existing Britannia Bridge. The crossing would have wind protection to avoid road closures during stormy weather, which is often a problem with the existing Britannia Bridge.

The third Menai crossing would be funded by the Welsh Government – but it is hoped the National Grid would contribute financially to the construction in return for carrying their cables on the new bridge, instead of building a £100m tunnel underneath the Menai Strait.

The Welsh Government’s budget, announced on Tuesday, includes an extra £3m towards the design and development of the bridge.

There are currently two Menai Strait crossings – the Menai Bridge, which was built by Thomas Telford in the 1820s, and Robert Stephenson’s Britannia Bridge, which was opened to carry rail traffic in 1850 but was rebuilt in the 20th Century to also carry road traffic.

Plans for a third crossing have been in the works since a consultation in 2007.

Dewi Williams, Anglesey council’s head of highways, said: “We have been here 10 years ago. It would be nice to think that something positive happens this time.

“The problem we have is that with high winds or an accident on the [Britannia] bridge it has to be closed.”

But Gwyn Morris Jones, ex-secretary of Ynys Mon Campaign for the Protection of Rural Wales, said a new bridge was not necessary.

“I have never been held up more than 10 minutes on this bridge and many of those who have been are used to holds-ups, because they come from large cities,” he said.

A public consultation is planned for early 2018 with a preferred route announcement in May.