Which dumbbell or two-bridge roundabout GSJ in England would you prioritise for a freeflow right turn?

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Which dumbbell or roundabout GSJ in England would you prioritise for a freeflow right turn?

A15/A180/M180
0
No votes
A34/M40
18
39%
A38/M1
2
4%
A41/M25
0
No votes
A45/M1
1
2%
A50/A500
2
4%
A130/A12
2
4%
A174/A19
1
2%
A331/A31
0
No votes
A331/M3
0
No votes
A419/M4
3
7%
A421/M1
2
4%
A500/M6 (J16)
1
2%
A556/M6
7
15%
A630/M1
0
No votes
A5300/A562
0
No votes
A404(M)/M4
1
2%
M50/M5
1
2%
M58/M6
1
2%
M180/M18
4
9%
 
Total votes: 46

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Steven
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Re: Which dumbbell or roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by Steven »

Chris5156 wrote: Mon Nov 08, 2021 21:11
B6047 wrote: Mon Nov 08, 2021 11:50 I cant think of any way of doing this but the right turn at M1 Junction 21 from A5460 Leicester/Fosse Park to M1 north really is in need of a freeflow access.
The entire junction complex, covering M1 J21, the junction with the Outer Ring Road, the two horrible signalised roundabout monstrosities on Narborough Road, and the various other signalised accessories leading to business parks and retail parks, would ideally be razed to the ground with a targeted bombing campaign and replaced with something else altogether. It's an absolute failure of land use and transport planning.
Probably replaced by, you know, the original plans for the ORR et al rather than the desperate bodge that's there now.
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Re: Which dumbbell or roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by M4Simon »

thatapanydude wrote: Mon Nov 15, 2021 10:50
M4Simon wrote: Mon Nov 08, 2021 09:27
thatapanydude wrote: Sun Nov 07, 2021 00:38 South Mimms: A1 north to M25 east and likewise M25 west to A1 south.
My priority here would be M25 westbound to A1(M) northbound. It's a long way round that roundabout to turn north.

If I'm going from the A1(M) southbound to M25 westbound (and I do, reasonably frequently), I usually go via the A414 and A1081 to M25 J22. That's usually a bit quicker than the A414/A405 North Orbital route to M25 J21.

Simon
I would agree though I would tackle this through either a new dual carriageway from the A1(M) j2 to M25 J22 broadly following the line of Coursers Road or upgrading the A414 and A1081 with some GSJ and widening.
I know too many people in Colney Heath and Roestock to support that.

When heading towards the A1(M) northbound, I'll either take the A405/A414 or the A1081 or the A1(M) depending on which my phone thinks will be quickest at the time. The left turn at South Mimms from M25 onto the A1(M) is usually ok. It is the right turns that cause the problems on that roundabout.

The A1081 route towards the A1 is painful as it involves nearly a full circuit of the London Colney roundabout. Going the other way, it is a quick left onto the A1081 from the A414, nearly always quicker than fighting to stay on the A414 and negotiating Park Street.

Simon
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Re: Which dumbbell or roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by jackal »

Rob590 wrote: Mon Nov 08, 2021 12:04 A1(M) south onto M18 south-west not listed? I suppose at the moment the impact of a freeflow right turn might be limited by the broader lack of capacity on the A1 around Doncaster anyway, but the queues do back up from there.
This was included in the similar poll for stackabouts that I made years ago:

viewtopic.php?f=1&t=19910
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Re: Which dumbbell or roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by Bryn666 »

Bignells Corner would benefit if just this was done. It also has the benefit of using that Ringway 3 stump...
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Re: Which dumbbell or roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by KeithW »

jackal wrote: Mon Nov 15, 2021 16:15
Rob590 wrote: Mon Nov 08, 2021 12:04 A1(M) south onto M18 south-west not listed? I suppose at the moment the impact of a freeflow right turn might be limited by the broader lack of capacity on the A1 around Doncaster anyway, but the queues do back up from there.
This was included in the similar poll for stackabouts that I made years ago:

viewtopic.php?f=1&t=19910
I would hope this would be part of the Darrington-Redhouse and Doncaster bypass scheme, that junction as you say often tails back along lane 1 almost as far as Warmsworth.
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Re: Which dumbbell or roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by C83 »

Quite a few obvious omissions in there.

M8 East <> M73 South - Needed since the M74 was completed to bypass the M8 through Glasgow
A725 North <> M74 South - After years of roadworks it's no better than it was before, if it wasn't for the above the extra few miles via M73 would be worth considering.

Edit: Just realised you had M58<>M6N on the options.
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Re: Which dumbbell or roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by jackal »

C83 wrote: Tue Nov 16, 2021 21:18 Quite a few obvious omissions in there.

M8 East <> M73 South - Needed since the M74 was completed to bypass the M8 through Glasgow
A725 North <> M74 South - After years of roadworks it's no better than it was before, if it wasn't for the above the extra few miles via M73 would be worth considering.
I agree these links are required. I've edited the title to make it clearer that the thread's about dumbbells and two-bridge roundabout GSJs rather than stackabouts. (The poll phrasing is unchanged.)
Last edited by jackal on Wed Nov 17, 2021 10:37, edited 1 time in total.
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Re: Which dumbbell or roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by M4Simon »

Bryn666 wrote: Tue Nov 16, 2021 09:51 Bignells Corner would benefit if just this was done. It also has the benefit of using that Ringway 3 stump...
Yes, that's the scheme I had in my head. One of the issues is that the weaving length to J24 is barely 2km, though I think it could be made to work by nudging the link road a little closer to the back of the MSA and tightening some radii.

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Re: Which dumbbell or roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by jackal »

M4Simon wrote: Wed Nov 17, 2021 08:54
Bryn666 wrote: Tue Nov 16, 2021 09:51 Bignells Corner would benefit if just this was done. It also has the benefit of using that Ringway 3 stump...
Yes, that's the scheme I had in my head. One of the issues is that the weaving length to J24 is barely 2km, though I think it could be made to work by nudging the link road a little closer to the back of the MSA and tightening some radii.

Simon
Good point, and note as well that this plan requires 1km of new M25 AC carriageway, as well as the link road. I like the idea of course but it may not be cost effective compared to putting in a loop in the SW quadrant of J23 like Tarbock Island (the proposals for Brook St and Simister are similar).

M25 J23 - Copy.png
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Re: Which dumbbell or roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by Peter Freeman »

jackal wrote: Wed Nov 17, 2021 10:30 Good point, and note as well that this plan requires 1km of new M25 AC carriageway, as well as the link road.
Not if the link to A1(M) saved one bridge and diverged on the right (it's OK ... only kiddin' !).
I like the idea of course but it may not be cost effective compared to putting in a loop in the SW quadrant of J23 like Tarbock Island (the proposals for Brook St and Simister are similar).
Yes, the loop's nearly as good, and much cheaper. The opposite direction could still take Bryn's route, requiring no structures and little land. It's not an essential element, but left turners then need not contend with going past the Services arm.

edited to correct M1 to A1(M).
Last edited by Peter Freeman on Wed Nov 17, 2021 22:36, edited 1 time in total.
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Re: Which dumbbell or roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by Chris5156 »

Peter Freeman wrote: Wed Nov 17, 2021 11:30
jackal wrote: Wed Nov 17, 2021 10:30 Good point, and note as well that this plan requires 1km of new M25 AC carriageway, as well as the link road.
Not if the link to M1 saved one bridge and diverged on the right (it's OK ... only kiddin' !).
A1(M) :wink:
I like the idea of course but it may not be cost effective compared to putting in a loop in the SW quadrant of J23 like Tarbock Island (the proposals for Brook St and Simister are similar).
Yes, the loop's nearly as good, and much cheaper. The opposite direction could still take Bryn's route, requiring no structures and little land. It's not an essential element, but left turners then need not contend with going past the Services arm.
The NE corner of the roundabout, where the access to the services joins, is easily the busiest and most congested part. Anything that gets some traffic off that part will do a lot to relieve the whole junction, so a left turn bypass would probably be easy to justify in terms of journey time improvements.
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Re: Which dumbbell or roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by Peter Freeman »

Chris5156 wrote: Wed Nov 17, 2021 13:30 A1(M) :wink:
Oops! Of course. Edited.
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Re: Which dumbbell or two-bridge roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by ChrisH »

Is it too soon to nominate M42 j5a...? :twisted:
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Re: Which dumbbell or two-bridge roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by Chris5156 »

ChrisH wrote: Thu Nov 18, 2021 09:11 Is it too soon to nominate M42 j5a...? :twisted:
:clap:
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Re: Which dumbbell or roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by Herned »

Chris5156 wrote: Wed Nov 17, 2021 13:30 The NE corner of the roundabout, where the access to the services joins, is easily the busiest and most congested part. Anything that gets some traffic off that part will do a lot to relieve the whole junction, so a left turn bypass would probably be easy to justify in terms of journey time improvements.
How bad is it these days? I used to live in that area and it was rarely more than irritating, as so much traffic to/from the west goes via the A414. Obviously free flow would be better, but I wouldn't have it very high up my priority list
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Re: Which dumbbell or roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by Chris5156 »

Herned wrote: Thu Nov 18, 2021 13:25
Chris5156 wrote: Wed Nov 17, 2021 13:30 The NE corner of the roundabout, where the access to the services joins, is easily the busiest and most congested part. Anything that gets some traffic off that part will do a lot to relieve the whole junction, so a left turn bypass would probably be easy to justify in terms of journey time improvements.
How bad is it these days? I used to live in that area and it was rarely more than irritating, as so much traffic to/from the west goes via the A414. Obviously free flow would be better, but I wouldn't have it very high up my priority list
I'm not a regular user any more - in fact it's probably heading for two years since I last went round there. But when I did use it semi-regularly the NE corner always seemed the worst. Simple left turns from A1(M) to M25 would queue back onto the sliproad and more than once I've spent the best part of an hour queueing to leave the services car park.
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Re: Which dumbbell or two-bridge roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by ais523 »

ChrisH wrote: Thu Nov 18, 2021 09:11 Is it too soon to nominate M42 j5a...? :twisted:
The design for that already has a freeflow right. There are no conflicting movements. (The fact that it goes around two roundabouts for no obvious reason means that it can't be taken at speed, but that doesn't prevent it being freeflow because there's no situation in which you'd ever have to stop for traffic.)
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Re: Which dumbbell or two-bridge roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by Chris5156 »

ais523 wrote: Fri Nov 19, 2021 21:15
ChrisH wrote: Thu Nov 18, 2021 09:11 Is it too soon to nominate M42 j5a...? :twisted:
The design for that already has a freeflow right. There are no conflicting movements. (The fact that it goes around two roundabouts for no obvious reason means that it can't be taken at speed, but that doesn't prevent it being freeflow because there's no situation in which you'd ever have to stop for traffic.)
Fine for now, but the second phase will see a service area built off the junction, north facing sliproads and signalisation :(
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Re: Which dumbbell or two-bridge roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by jackal »

ais523 wrote: Fri Nov 19, 2021 21:15
ChrisH wrote: Thu Nov 18, 2021 09:11 Is it too soon to nominate M42 j5a...? :twisted:
The design for that already has a freeflow right. There are no conflicting movements. (The fact that it goes around two roundabouts for no obvious reason means that it can't be taken at speed, but that doesn't prevent it being freeflow because there's no situation in which you'd ever have to stop for traffic.)
The two roundabouts will be complete rather than dogbonised, so the right turn has a give way at both roundabouts, as per the general arrangement. (I suspect the left turn will give way as well, though the drawing nonsensically omits the dashed lines.)

https://infrastructure.planninginspecto ... _Plans.pdf
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Re: Which dumbbell or two-bridge roundabout GSJ in England would you prioritise for a freeflow right turn?

Post by Bryn666 »

jackal wrote: Sun Nov 21, 2021 18:56
ais523 wrote: Fri Nov 19, 2021 21:15
ChrisH wrote: Thu Nov 18, 2021 09:11 Is it too soon to nominate M42 j5a...? :twisted:
The design for that already has a freeflow right. There are no conflicting movements. (The fact that it goes around two roundabouts for no obvious reason means that it can't be taken at speed, but that doesn't prevent it being freeflow because there's no situation in which you'd ever have to stop for traffic.)
The two roundabouts will be complete rather than dogbonised, so the right turn has a give way at both roundabouts, as per the general arrangement. (I suspect the left turn will give way as well, though the drawing nonsensically omits the dashed lines.)

https://infrastructure.planninginspecto ... _Plans.pdf
That's going to be a complete horror show when the northern slips and MSA inevitably go in. Funny how on another thread freeflow interchanges that remove vehicle conflicts and emissions so tick two boxes are being criticised as too complex and dangerous but providing absolute dog crap like this with substandard weaving lengths, because the M42 really needs more weaving and induced traffic, is all fine.
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