For those that support the ‘Full South’ Concept (SYSTRA report) as their preferred solution to the A27 at Chichester, I would invite them to have a look at the A3 Kingston bypass because that is likely to be the outcome.
Remember that ‘underpasses’ are not necessarily ‘tunnels’; they are more likely to be just overbridges for the roundabouts with the trunk road in cutting and the sides supported by concrete retaining walls.
In order to accommodate slip roads on and off the A27 at every junction, the overall road width at the approaches to the junctions would need to be at least six lanes.
How this is all achieved really is a challenge with lakes, the canal, the railway line, a high water table, underground services and no doubt plenty of unforeseen conditions to deal with.
Construction would last for about five years with just one lane of traffic in each direction kept open for the A27.
There would be numerous closures and diversions for local traffic.
A 24/7/365 breakdown service would need to be provided to remove broken down vehicles off the road.
Imagine the congestion and pollution that would ensue throughout the city and surrounding area as people try to find alternative routes.
All this would be severely damaging to local businesses.
The ‘mitigated north concept’ is the obvious long term solution.
Bob Probee (Retired Highway Engineer), Conifer Drive, Hambrook