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WHBM wrote:Just from casual observation at the M5 roundabout, the principal flow from the A358 appears to be into Taunton. This is quite common, even on trunk roads, that the nearest major centre generates the principal flow. After that, there seems as much turning right, towards Bristol, as left, towards Exeter. This is the signed route from Yeovil, and indeed Weymouth, to Bristol.
Neither of these flows would benefit from a new link to further down the M5.
If the A358 is dualled, I wonder what will be done about the various junctions along the way. Grade separated seems out of fashion. You try even nowadays getting from Hatch Beauchamp village towards Taunton.
Your observation is pretty much right:
As I've mentioned previously, 'straight over' grade separation (i.e. a stackabout) would be a good option if it fitted, though it probably doesn't. But even A358e<>M5n is busier than the 'strategic' route so they can at least try to accommodate that, as the trumpet option would do.
All the junctions will be grade separated, except Southfields will probably be bundled with the follow on Ilminster bypass scheme.
I'd always thought hamburgerising the western part would have merit if nothing more radical was proposed.
The business park steals capacity from the circulatory as the traffic to there from Taunton uses the entire roundabout on a local move reducing capacity for more strategic and regionally significant flows.
A double cut through so the A358SB to business park, the M5NB - A358SB and the A358NB-M5NB flows were removed from having to completely navigate the circulatory.
There is plenty of room on that side where the circulatory was previously enlarged.
It might need a little more work to get shovel ready...
RichardA35 wrote:I'd always thought hamburgerising the western part would have merit if nothing more radical was proposed.
The business park steals capacity from the circulatory as the traffic to there from Taunton uses the entire roundabout on a local move reducing capacity for more strategic and regionally significant flows.
A double cut through so the A358SB to business park, the M5NB - A358SB and the A358NB-M5NB flows were removed from having to completely navigate the circulatory.
There is plenty of room on that side where the circulatory was previously enlarged. M5J25.jpgIt might need a little more work to get shovel ready...
I would have thought it would make more sense to provide local access to the business park (mainly just offices rather than anything with a lot of HGV traffic) on the basis that most office workers probably live in the town rather than in Bridgwater or Exeter, so a lot of unnecessary journeys all around that already congested roundabout.
In my experience the traffic lights for the park and ride on the A358 are the biggest problem, in the PM peak they regularly cause the southbound side of the roundabout to lock up slowing the whole A358 coming from Taunton.
The business park traffic to and from Taunton is pretty much opposite to the peak direction so must have limited impact on the roundabout, although providing some sort of access from Blackbrook Way can’t hurt. It would need some measures to avoid it being used as a shortcut to the motorway though
The map and aerial views show that Blackbrook Park Avenue could be linked to Blackbrook Way at the southern end, by skirting a playing field. Then, Ilminster Rd, the old A358, could be reconnected as well. I guess they don't want another busy arm but, using J25 to get from Taunton to another bit of Taunton isn't helpful. Joining the 2 Blackbrook roads without reconnecting the old A358 may be a compromise.
I came across this roundabout last year when on a weekend 'jolly' with the Jaguar Enthusiasts Club. We were staying at the Holiday Inn that is just off it.
The council in their wisdom, have blocked access to the roundabout via the very obvious Ilminster Road, no doubt to appease the residents. A short length of road has been made buses only 24x7. In doing this they force all those who live in Taunton (especially to the west side), and work in the Business Park, to use the dual carriageway "Toneway" and then circumnavigate the roundabout. It really does clog up remarkably quickly so the council needs to engage with Highways England to make some improvements. Will this happen ? I suspect not. Ilminster Road runs west into Hamilton Road and a brief glance at Bing Maps shows it would provide a lovely short cut to the motorway from the west side of Taunton,hence it being blocked so satisfy the locals. So now the "Toneway" road is overloaded and made even worse by a series of retail and other developments along its short length. What this whole affair shows is that spatchcock after spatchcock eventually leads to complete chaos.
jackal wrote:As I've mentioned previously, 'straight over' grade separation (i.e. a stackabout) would be a good option if it fitted, though it probably doesn't.
If the retail park wasn't in the way an upgrade similar to the M40/A46 would work. Take the new A358 north through where the Sainsbury's car park and the Travelodge are with it ending on the current A358 roundabout by B&Q and serve the current M5 junction with a fork on the A358 just to the east of the current junction, ideally just at or just before where the primer inn is. Too much in the way for that option I think.
jackal wrote:But even A358e<>M5n is busier than the 'strategic' route so they can at least try to accommodate that, as the trumpet option would do.
WHBM wrote:Just from casual observation at the M5 roundabout, the principal flow from the A358 appears to be into Taunton. This is quite common, even on trunk roads, that the nearest major centre generates the principal flow. After that, there seems as much turning right, towards Bristol, as left, towards Exeter. This is the signed route from Yeovil, and indeed Weymouth, to Bristol.
This is the main problem: the A358 isn't, and is unlikely to be, part of the London - SW route but is being pushed as this to avoid the issues with upgrading the A303/A30 route through the Blackdown Hills but still create an M3-M5 link. This in itself isn't a problem, the A358 is in more need of upgrading than the A303/A30 through the Blackdown Hills as it's an important link into Taunton and as a link to Bristol and the North via the M5. The problem is that this upgrade not only neglects, but makes no provision for, the job the A358 actually does. For that reason I expect it will get kicked into the long grass, again!
There's absolutely no chance of making the existing junction a three level stackabout. There's just too much development alongside Toneway.
I do have a solution but it's costly and ecologically it's a non-starter but here goes. Divert Toneway from its junction with Admiralty Way eastwards along a new alignment adjacent to the railway. Move J25 to a point halfway between Sainsbury's and where the M5 crosses the railway. A358 east of here follows a straight line from the new J25 running east of Woodlands Castle to rejoin the existing road east of the P&R. The major issue for the diverted Toneway is what to do with the river - either put it underground or move it.
How would you like your grade separations, Sir? Big and complex.
Taunton, just like Weston to the north, has grown immensely since the motorway was built, and is now strangled by the single junction. I'm sure that many years ago there was a debate in the local papers about getting a second junction built for the town (probably just a handful of local 'campaigners' making a lot of noise). However, looking on the map, a junction on the M5 between Corfe and Trull, connected to the B3170 and an upgraded Trull Road could take quite a chunk of traffic away from the Toneway. It could also be connected to the A358 near Hatch Beauchamp.
Flippin expensive of course, and a complete fantasy, but a growing town of 65000 people with only one connection to its bypass is utterly absurd.
Rob. My mission is to travel every road and visit every town, village and hamlet in the British Isles.
I don't like thinking about how badly I am doing.
Traffic from the west side of Taunton heading south uses j26, which is also signed for Taunton heading north on the M5.
There have been occasional mentions, including in official reports about the addition of north-facing slip roads onto the M5 from the A361, to support the development on the east side of Monkton Heathfield as well as relieving j25. As far as I remember that hasn’t been adopted by the council as part of the strategy though.
Crayons out fantasy solution to j25: how about building a car only (~2.5m clearance) single lane each way underpass to make it a stackabout? Would need some hefty pumps but there would be space as the ramps down would only need to be 60m long
rileyrob wrote:However, looking on the map, a junction on the M5 between Corfe and Trull, connected to the B3170 and an upgraded Trull Road could take quite a chunk of traffic away from the Toneway. It could also be connected to the A358 near Hatch Beauchamp.
Flippin expensive of course, and a complete fantasy, but a growing town of 65000 people with only one connection to its bypass is utterly absurd.
The HE proposal consulted on last year had a new junction between the M5, new A358 and B3170.
It would have been completely mad IMO as it would make the B3170 (S2 with hundreds of residential property frontages) the main way into Taunton from the south. It didn't seem to go down well, hence the new consultation.
Herned wrote:Traffic from the west side of Taunton heading south uses j26, which is also signed for Taunton heading north on the M5.
There have been occasional mentions, including in official reports about the addition of north-facing slip roads onto the M5 from the A361, to support the development on the east side of Monkton Heathfield as well as relieving j25.
This is a better idea, as the A38 going towards Taunton is at least dualled before dividing traffic between the A38 and A3259.
This would certainly relieve Jn 25 and Toneway. However one must always think cautiously, because any new junction would inevitably lead to demands for development along the A38/A361, and, of course the A3259 into Taunton. The good thing is that the traffic would be dispersed. At the moment it all has to go along Toneway
The odd thing about that map is that the diagram very clearly shows connecting roads to the local network, when HE are adamant that the junction would not have any such links (see FOI request https://www.gov.uk/government/publicati ... uthorities)
fras wrote:Or even a full junction at the A361 bridge.
This would certainly relieve Jn 25 and Toneway. However one must always think cautiously, because any new junction would inevitably lead to demands for development along the A38/A361, and, of course the A3259 into Taunton. The good thing is that the traffic would be dispersed. At the moment it all has to go along Toneway
The local plan is for development all the way to the A361, so that ship has sailed!
I don't know if you could actually get it past the building north of the roundabout, but it's only Homebase in any case.
As the next roundabout north (off the top of the image) is very close, the northbound merge would have to be signalized.
It was those reasons which made me quickly abandon any idea of an online solution.
Here's a map of my offline proposal I made last night. The existing J25 could remain but the north facing slips would either have to close or just feed into the new junction.
Just a minor point that Homebase has closed down and it's now The Range.
Improving access for the A358 into Taunton is utterly pointless - all the traffic with just crash to a halt at Creech Castle even quicker and it may even end up making J25 worse. Getting traffic out of Taunton quicker may have some merit - something like this at Newport could work well. And a J24A at the A361 would definitely help, especially if there could be a Monkton Heathfield bypass to go with it.
DavidBrown wrote:Just a minor point that Homebase has closed down and it's now The Range.
Improving access for the A358 into Taunton is utterly pointless - all the traffic with just crash to a halt at Creech Castle even quicker and it may even end up making J25 worse. Getting traffic out of Taunton quicker may have some merit - something like this at Newport could work well. And a J24A at the A361 would definitely help, especially if there could be a Monkton Heathfield bypass to go with it.
There are plans to update creech castle junction with a "throughabout"
