Environmentalists welcomed the government's rejection of the £150M Hastings Bypass this week.
But they feared approval of the environmentally sensitive dualling of the A66 across the Pennines will follow hot on its heels.
Consultant Maunsell is expected to recommend the scheme this week in a study it has carried out for the government.
Transport secretary Stephen Byers scrapped the Hastings scheme because the road would not to bring regeneration benefits to the most economically deprived area of the town. Instead, improved local rail services, a new rail station and better bus services are expected. East Sussex County Council has been asked to submit extra schemes for Hastings in its Local Transport Plan.
The Highways Agency has been asked to dual the A21 to four lanes to improve access to Hastings.