A dual carriageway would be highly visible in the landscape as well as noisier than the present road. An off-line single or dual carriageway new road as preferred by some would also be highly intrusive at this point.
In the Autumn Statement, the Government has nominally ‘allocated’ £75 million to address issues on the A27 between Lewes and Polegate. This is far below what would be needed for a new road, but it would be enough to tackle safety issues at Wilmington, Selmeston and elsewhere.
These sorts of measures are unlikely to have a significant impact on the National Park and could lead to improved access by walkers and cyclists into the park (across the A27).