Wokingham District Council will launch a legal bid to prevent neighbouring Reading turning its ring-road into a giant one-way system.
Plans to turn Reading's IDR into a one way system could yet stall
At a meeting on Monday, Reading Borough Council's cabinet rubber-stamped a decision for a £9m transformation of its Inner Distribution Road (IDR).
Reading said the plan is essential to ease congestion on the IDR.
But councillor Frank Browne, the leader of Wokingham council, said they were concerned about knock-on consequences.
Commenting on the decision, Cllr Browne told BBC News: "It's disappointing.
"We asked Reading to allow for further time for detailed analysis of their traffic model, which we believe may be flawed.
"We will seek legal action to seek a delay and perhaps a stop to the IDR."
Cllr Browne criticised the anti-clockwise IDR plan claiming it only looked at peak traffic rather than traffic throughout the day, it was based on "old" data, and that they wanted a more detailed look at the implications for Wokingham residents in areas such as Shinfield and Sonning.
But Councillor John Howarth, Reading's lead councillor for strategic planning and transport, defended the plan saying Wokingham's criticisms were more about political posturing than real concerns.
He told the BBC that the model complies with accepted methodology, that it was based on 2001 data, which has since been updated and that it would have been a waste of Reading tax payers' money to compile a Berkshire model.
"We think it (the IDR plan) is essential to ease our congestion issues," he said.
"We have to find a way of managing our traffic."
But Cllr Browne confirmed that Wokingham council has taken legal advice and will be challenging the decision as soon as Reading secures a traffic order.