Our understanding is that the proposed changes to the junctions of the A27 are very similar to those that were contained in Option 3a of the Highways England consultation (restricting right turns from the southern approaches to the A27 at the Stockbridge Road and Whyke Road roundabouts). These proposals were rejected at the time as being completely unfair and disruptive to local residents in favour of 'out of town' commuter and goods traffic.
Furthermore, the disruption that these 'minor improvements' would cause for up to three years (and no doubt longer if the simple bridge project is anything to go by) would also call into question the viability/cost v benefit of such proposals.