As many of you may know, plans for the junction at Tipner on the M275 were resurrected a few years back, having been shelved mid-build in the 1970s. The junction will serve a bus park and ride site, hence the bus lane on the southbound onslip on the plans.
According to Portsmouth City Council, there are three options:
Option 1
Option 3
Option 9A
Option 1 is a diamond interchange, with the road passing under the northern bridge (currently unused). This seems to be out of favour though, and so is the least likely to get built.
Option 3 is a roundabout interchange, much like the original plan, and utilises both bridges. This is the option preferred by the planners.
Option 9A is a peculiar junction with a couple of very tight looking slip roads and a strange layout, utilising the southern bridge. This option was suggested by local residents; probably NIMBYs in the houses next to the proposed southern onslip in options 1 and 3, hence the slip road being further north.
Personally, I prefer option 3, as it utilises the existing half-built layout and is a simple and easy layout to use. Option 9A, the NIMBY option as I regard it, would require additional earthworks, have a more peculiar layout, and have a couple of very tight slip roads, which obviously, in the eyes of safety, isn't as safe. The additional deceleration and acceleration on the inbound M275 would also create a greater safety risk and increase congestion in my mind.
The final plan hasn't been decided upon yet, but personally, I hope the planners stick with their favourite option rather than the NIMBY option. Work will start, at the earliest, in 2008, so there is time for a little trip down there in the summer to take lots of photos
Oh, and one final thing, do other Sabristi reckon the already built subways will be used, or filled in? Quite a few subways were filled in and replaced with at-grade crossings a few years back, and footbridges removed too, so I don't rate their survival as being too good. Photos, photos!
