Campaigners have raised concerns that plans for an Oxford to Cambridge expressway have been resurrected.
The Department for Transport paused work on the controversial plan in March but a new economic prospectus states the need for link roads in the area.
Helen Marshall, from the Campaign to Protect Rural England (CPRE), said it alluded to the "expressway in all but name".
Those behind the so-called Oxford-Cambridge Arc deny the claims.
The Arc incorporates areas of Oxfordshire, Northamptonshire, Buckinghamshire, Bedfordshire and Cambridgeshire.
It aims to invest in the science and technology industries in the area which it says generate more than £111bn for the economy each year and could be increased to £200bn.
But the additional house building and road infrastructure will negatively impact the countryside, campaigners fear.
Ms Marshall, director of CPRE Oxfordshire, said: "[The document] definitely talks about needing to look again at road links between the M40 and the A14 around Cambridge.
"The level of development that is envisaged could rapidly change Oxfordshire and its rural character and I don't think that is what most people in Oxfordshire would like to see."
The document suggests Oxford and Milton Keynes routes could be reassessed "to channel investment more effectively".
Barry Wood, from the Arc Leadership Group, said just because the expressway had stalled it "doesn't mean that you couldn't have improvements to other parts of connectivity".
"Settlements that are in-between Oxford and Milton Keynes may well need bypasses round them," he said.
"The area between Oxford and Cambridge is always going to be an area for investment and growth, what's going to be important is that's done properly and has environmental gains as well as business gains."
The leadership group will learn whether it gets further investment from the government in the upcoming comprehensive spending review.