IAN wrote: ↑Fri Nov 27, 2020 17:30Are there any plans to GSJ the roundabouts at Glynneath and Resolven so that the route is completely free-flowing between Abergavenny and Neath when sections 5 and 6 are completed?
I haven't seen any plans for this.
The trouble with rebuilding those junctions is that the A465 carries 15-20k AADT between Merthyr and Aberdulais. That figure is high enough to make a single carriageway road unacceptably busy, and produce congestion and an accident rate that justify a dualling project. And if you're carrying out a dualling project, there's no reason not to provide GSJs throughout.
However, where a dual carriageway exists, is carrying 15-20k AADT, and indeed is only about 30 years old (so has been built to more or less current standards and has plenty of life left in its carriageways and structures), there isn't much of a case to be made for reconstructing flat roundabouts as GSJs. Traffic levels and accident rates just won't justify it. You could make a political decision to do it anyway, to complete the expressway route, but you'd be prioritising a free-flowing route that's received plenty of recent investment over other sites that potentially have bigger congestion issues and higher accident rates.
Perhaps when the Dowlais-Hirwaun scheme is complete there will be some impetus to GSJ the flat junctions at Glynneath, Resolven, Abergavenny and Raglan, on the basis that further improvements will relieve the M4, or because the improved route has generated new journeys that mean those roundabouts have become congested. But I can't see it coming on to the agenda for another 10 years or so.
All things considered, it's a real shame that flat roundabouts were used to save a bit of money when those bits were dualled, because that was the time to do it.