I read your report about the rethink on the A27 this week and I have the following thoughts.
We live in a large urban community in a beautiful part of Sussex bounded on the south but the sea and in the north by the South Downs.
At present it is divided by an ugly scar running through its centre which generates noise, pollution and much inconvenience. I mean of course the A27.
The most logical approach to my mind would be to divert the road to the north so ensuring the cohesion of the entire community.
However, if this is not possible for proven and valid reasons then the next best thing would be to put the unsightly and noisy dual carriageway in a cutting starting west of the Tesco roundabout and ending to the east of the Sainsbury roundabout. All the existing roundabouts would remain at street level and communications from north south would be retained and indeed improved.
I asked the consulting engineer from Mott MacDonald if this option had been considered. He said it had not but it would be too expensive. Had this been checked? No, he said. Why not? No answer. It really is the only acceptable solution if the northern route is not possible in my opinion.