A rethink is being urged over £53million-plus plans which aim to cut congestion on the A12 between Nacton and Melton.

Opponents say there needs to be more focus on sustainable transport and a strategy which prioritises low-carbon and public transport.

Suffolk County Council plans to upgrade the A12 between the Seven Hills and Woods Lane junctions with proposals including a new dualled section between the Seckford and Dobbies roundabouts on the edge of Woodbridge, as well as traffic lights on some of the junctions, possibly only used at peak times.

Officers say the work is needed to deal with growing traffic demands with projections suggesting vehicles will increase by a quarter by 2040 - with nearly 47,000 daily vehicle movements around the Martlesham junctions by then.

Woodbridge Liberal Democrat councillor Caroline Page said: “Trying to cure congestion by adding more capacity is like trying to cure obesity by loosening your belt.”

The existing plans do include pedestrian and cycle improvements, such as a dedicated cycle route on the new dualled section and new pedestrian and cycle bridges over the A12 in Martlesham.

Opposition councillors from the Green, Liberal Democrat and Independent (GLDI) group said more was needed to promote the shift away from private vehicles.

Councillor Keith Welham, GLDI spokesman for transport, said: “Cabinet approval of these proposals continues the trend of spending large sums of money to encourage use of private vehicles and goods haulage by road.

“What is really needed is a package of cycling and public transport measures to reduce the need to drive and avoid the environmental damage which results from major road improvements.”

“I welcome the improvements for cyclists, pedestrians and buses; we need to ensure that there are safe and convenient options for commuters into Ipswich reducing reliance on private car use.”

Suffolk County Council’s Conservative cabinet last week discussed the scheme, with plans to pursue an outline business case and a financial ask of the Department for Transport.

Richard Smith, Conservative cabinet member for economic development, transport strategy and waste, previously said: “If we did nothing we know that the traffic would get much worse, so the kind of things we are planning to do will keep the traffic moving and will give positive improvements with a new section of dual carriageway.”