Coomera Connector, Australia.

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Peter Freeman
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Coomera Connector, Australia.

Post by Peter Freeman »

This motorway project has been mentioned already (p8 of 'Australian Motorways' topic in 'International Roads' forum), but I'm starting this topic to record its progress over the next few years.

Gold Coast is a major and growing city 100km south of Brisbane, to which it is connected by the M1 Pacific Motorway. M1 continues north and south along the east coast, but is congested where it passes close by Gold Coast because its strategic traffic is supplemented by local commuters. Coomera Connector's purpose is to relieve M1 of this local traffic. Construction will be staged: Stage 1 (consisting of north, central and south packages), and Stage 2. Stage 1 north has begun.

To start, here are some links.

Project website -
https://www.tmr.qld.gov.au/projects/pro ... -connector

Background video -
https://www.youtube.com/watch?v=fkRWpD2h8Ws

Stage 1 (mainly central package) simulated fly-over -
https://www.facebook.com/watch/?v=607372123211791

Stage 1 north detailed layout -
https://www.tmr.qld.gov.au/_/media/proj ... tage-1.jpg

Drone view -
https://www.youtube.com/watch?v=pEynTpWsUz8
(0m00s-1m23s is Stage 1 north, 1m23s-3m12s covers most of unstarted Stage 1 Central)

Stage 2 simulated fly-over -
https://www.youtube.com/watch?v=pRckRAd0jjk&t=0s

edit: add a reference to previous mentions in another topic
edit: drone view update
Last edited by Peter Freeman on Tue Jun 11, 2024 09:06, edited 3 times in total.
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Re: Coomera Connector, Australia.

Post by Truvelo »

A bit disappointing to see the junctions are plain diamonds with left filter lanes. I would have expected SPUI or DDI these days.
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Re: Coomera Connector, Australia.

Post by Peter Freeman »

Truvelo wrote: Fri Dec 15, 2023 10:43 A bit disappointing to see the junctions are plain diamonds with left filter lanes. I would have expected SPUI or DDI these days.
A bit disappointing, yes, especially in Queensland, Australia's most progressive state for interchange innovation. However, AU is still in the 'pilot' phase for its DDI's: three in operation, one under construction, three planned. Our default is still the diamond. This might still be the case in USA too (with exceptions MO and KS), despite USA now having >80 operational DDI's.

SPUIs are well-established here though (total in 2024 = 37).

edit: AU SPUI total added.
Last edited by Peter Freeman on Sat Jun 08, 2024 05:43, edited 2 times in total.
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Re: Coomera Connector, Australia.

Post by Peter Freeman »

For consolidation, I'm re-posting some earlier discussion from 'Australian Motorways' topic.
Last edited by Peter Freeman on Thu Jun 06, 2024 09:26, edited 1 time in total.
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Re: Coomera Connector, Australia.

Post by Peter Freeman »

Peter Freeman re-post:
Coomera Connector Stage 2 flyover (artist's impression) is available.It confirms that the northern terminus, at Pacific and Logan Motorways, will be 6/8 movements.
https://www.youtube.com/watch?v=pRckRAd0jjk&t=0s
Jackal wrote:It's interesting that the northern terminus is an offside/TOTSO configuration - I guess this is because the Pacific Motorway movements will be dominant though it might just be easier to fit onto the existing interchange.
The Coomera-Brisbane turn will definitely dominate. Also, as I've opined before, AU will accept an offside exit if it's anywhere close to balanced (subject to weaving elimination). Easier to fit - yes, that too. I'd like to think that that's because the Logan Motorway was designed with this extension in mind.
Jackal wrote:They also seem to be excising the local movements from the southbound to westbound turn, I suppose for buildability or to eliminate the current weaving space here:
https://www.google.co.uk/maps/@-27.6883 ... ?entry=ttu
I hadn't noticed that. It must be for weaving elimination, since it could easily have been retained. I notice an extra local road (or is it just a bike/pedestrian track?) spanning the M1, though it might not replicate that lost movement.
Jackal wrote:The thought about buildability was that the local ramp that currently feeds into the weaving space is right in the way of the viaducts for the southbound connector.
Ah, yes, and so probably a good pragmatic removal. Mind you, it's surprising how cleverly viaducts can be supported on widely-spaced uprights and a lintel.
Jackal wrote:Curious that the other end of the scheme won't connect to the Pacific Motorway and just staggers onto the at-grade Nerang Broadbeach Road around here:
https://www.google.co.uk/maps/@-27.9978 ... ?entry=ttu
Yes, that struck me too, very early on, and I wondered who else it would jar on! You might say that it's rather 'Australian' though ...?

The reason: although CC was for some years referred to as 'the 2nd M1', it's not intended to be an M1 bypass. It's an internal road for GC's northern suburbs' use. By the time it reaches Nerang-Broadbeach Road, most traffic will have dispersed into GC. Even so, I don't like it much either! There are opportunities, a few km north, to merge it back to M1, as well as meeting NB Road.

edit: fixed up the quoting.
Last edited by Peter Freeman on Thu Jun 06, 2024 12:51, edited 7 times in total.
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Re: Coomera Connector, Australia.

Post by Peter Freeman »

Stage 1 Central is now beginning construction.

Here's a March 2024 Stage 1 Central Newsletter. Further information is accessible from links within -
https://www.tmr.qld.gov.au/projects/coo ... -1-central

Here's a Stage 1 Central detailed layout -
https://www.tmr.qld.gov.au/_/media/proj ... 145AD44013

The detail in the link above is not high resolution, so here's a way to view better detail. However, it's an early design version, and some details have changed -
https://coomeraconnector360.tmr.qld.gov ... tor&indi=1
(then refresh browser to make the image appear - I don't know why)
(then click on orange dots)

Here's a newsletter about Future Stages (=Stage 2) -
https://www.tmr.qld.gov.au/projects/coo ... ure-stages
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Re: Coomera Connector, Australia.

Post by Truvelo »

Peter Freeman wrote: Thu Jun 06, 2024 09:07 Here's a Stage 1 Central detailed layout -
https://www.tmr.qld.gov.au/_/media/proj ... 145AD44013
Northbound off-ramp to Gold Coast Highway where it crosses Realigned Buckler Drive. Is it possible for the scissors crossover to be replaced by a bridge and avoid having the set of lights.
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Re: Coomera Connector, Australia.

Post by Peter Freeman »

Truvelo wrote: Thu Jun 06, 2024 19:44
Peter Freeman wrote: Thu Jun 06, 2024 09:07 Here's a Stage 1 Central detailed layout -
https://www.tmr.qld.gov.au/_/media/proj ... 145AD44013
Northbound off-ramp to Gold Coast Highway where it crosses Realigned Buckler Drive. Is it possible for the scissors crossover to be replaced by a bridge and avoid having the set of lights.
That would be possible, though it's tight and skew at that point, sandwiched between the motorway and rail lines. The explanation for why not done, in addition to a minor cost saving, is philosophical: our pragmatic acceptance of signals (= non-obsession with freeflow). I've referred to this often, and it's quite marked in many AU designs. We do value freeflow for main movements (as in your great Sabre signature, Truvelo!), but we don't have tantrums when stopping at signals.

If you look in the link to earlier designs, you'll see that this interchange is the one most altered from the reference design. Buckler Drive was brought onto the west side of the motorway in order to improve access to the two railway stations. That shift, although creating the scissors-crossing, enabled the re-design at GC Hwy, which added an eb to sb 270 deg loop (freeflow - yay!) and allowed other simplification.

The get-out-of-jail card is that the scissors-crossing is close to the GC Hwy signalisation. It will be synchronised with those signals (and we're good at that). Thus, unless you're unlucky with your arrival timing, the signals probably won't add another halt for you.

I've remarked previously (and so have others) on the scissors crossing at M60 J26. I've not driven through that, but I presume it works ok. It doesn't significantly add congestion, because it only leads to other congestions that exist for other reasons. I think Bryn remarked that it has been known to confuse, but rarely (??). Needs good marking, good signage. Other signalised scissors exist. Pragmatism!
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Re: Coomera Connector, Australia.

Post by Peter Freeman »

Stage 1 South information released, and construction seems not far away.

Here's a link to the website -
https://www.tmr.qld.gov.au/projects/coo ... ge-1-south
Newsletter -
https://www.tmr.qld.gov.au/projects/coo ... newsletter
Detailed design -
https://www.tmr.qld.gov.au/_/media/proj ... r-2023.pdf
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Re: Coomera Connector, Australia.

Post by Peter Freeman »

Peter Freeman wrote: Thu Jun 06, 2024 08:52
Jackal wrote:Curious that the other end of the scheme won't connect to the Pacific Motorway and just staggers onto the at-grade Nerang Broadbeach Road around here:
https://www.google.co.uk/maps/@-27.9978 ... ?entry=ttu
Yes, that struck me too, very early on, and I wondered who else it would jar on! You might say that it's rather 'Australian' though ...?

The reason: although CC was for some years referred to as 'the 2nd M1', it's not intended to be an M1 bypass. It's an internal road for GC's northern suburbs' use. By the time it reaches Nerang-Broadbeach Road, most traffic will have dispersed into GC. ...
Ah, on looking at Stage 1 South detail layout, I see that the southern termination at signals will be temporary. At the interchange next north from there, Southport-Nerang Road, south-facing ramps are shown as 'proposed future connections'. This is a virtually certain clue that Nerang-Broadbeach Road will be further developed in future, at which time those missing ramps will be added and the signalized intersection converted to GSJ.

Another clue is that, 5 km south-east down N.B. Road, there is a roundabout future-proofed for flyover addition. Of course, GSRs are out in AU, so when that is required, it will be built as a different type of interchange. Let's hope SPUI or DDI.

Stage 1 South detail layout -
https://www.tmr.qld.gov.au/_/media/proj ... r-2023.pdf
(shows future ramps, creating a 4-ramp parclo = semi-folded diamond)

Location of future-proofed roundabout -
https://www.google.com.au/maps/place/Co ... FQAw%3D%3D
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Re: Coomera Connector, Australia.

Post by Truvelo »

Why does Australia hate GSRs?
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Re: Coomera Connector, Australia.

Post by Peter Freeman »

Truvelo wrote: Tue Oct 01, 2024 20:21 Why does Australia hate GSRs?
Wow, that's putting it a bit strongly! I don't think anyone in Australia, whether traffic engineer or motorist, would say that. Most AU drivers of course wouldn't know what a Grade Separated 2-bridge Roundabout is, because they'd hardly ever encounter one - the whole country has only about 20.

Since they're mainly a UK specialty, the more pertinent question is 'why does the UK love them?'.

I think my view on GSRs is well-known to some Sabre readers, and my simple answer to your question is: because they perform poorly relative to diamonds and parclos, except under light traffic load.

It's the old roundabout-versus-signals issue, whether at a motorway service interchange or an at-grade intersection of ordinary roads. A roundabout offers low delay under light load, but fails under duress. Signals handle heavy loading, but make you wait even when there's hardly anyone else in sight. If you always drive off-peak, you're going to love rbts, but at other times, which flavour of waiting do you prefer? Sitting facing a red for a minute or two, with reasonable confidence of quickly proceeding at the end of this cycle, or sitting for an unpredictable period of inching forward in a slowly-moving queue?

Why has Australia (and the USA, etc) realised this while the UK has not? We do have experience of a balance that was closer to UK's, but that balance has shifted as more and more rbts are converted to crossroads (etc), resulting in radical throughput increases. On the other hand, the UK rarely selects the at-grade signalised cross or the diamond motorway interchange; and when they are selected, they are built to a crippled form and scale, thereby obscuring the evidence.

Having said that, Australia obviously appreciates rbts in their appropriate setting, because we still build and use many.

There are varying positions between states here. WA/Perth leans somewhat towards rbts (for a curious reason discussed previously elsewhere), and SA/Adelaide a little. The main reason: WA and SA don't have many motorways, and don't have the heavy traffic of eastern cities. QLD formerly liked rbts too, but the penny dropped years ago, so you won't find them in new high-volume constructions.

In my home state of Victoria, main-road roundabouts are becoming extinct at a rate of about 5/year. A telling fact is that, of all the design aspects in capacity-increase projects, the one most promoted and appreciated is 'replacing the roundabout with signals'. This responds to the fact that, in public consultations prior to design finalisations, the most frequent complaint is 'delays at roundabouts'. This is their experience - and it's the same in the UK, but UK drivers seem prepared to just sit there and cop it.
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Re: Coomera Connector, Australia.

Post by jackal »

Peter Freeman wrote: Fri Oct 04, 2024 00:38
Truvelo wrote: Tue Oct 01, 2024 20:21 Why does Australia hate GSRs?
Wow, that's putting it a bit strongly! I don't think anyone in Australia, whether traffic engineer or motorist, would say that. Most AU drivers of course wouldn't know what a Grade Separated 2-bridge Roundabout is, because they'd hardly ever encounter one - the whole country has only about 20.

Since they're mainly a UK specialty, the more pertinent question is 'why does the UK love them?'.

I think my view on GSRs is well-known to some Sabre readers, and my simple answer to your question is: because they perform poorly relative to diamonds and parclos, except under light traffic load.

It's the old roundabout-versus-signals issue, whether at a motorway service interchange or an at-grade intersection of ordinary roads. A roundabout offers low delay under light load, but fails under duress. Signals handle heavy loading, but make you wait even when there's hardly anyone else in sight. If you always drive off-peak, you're going to love rbts, but at other times, which flavour of waiting do you prefer? Sitting facing a red for a minute or two, with reasonable confidence of quickly proceeding at the end of this cycle, or sitting for an unpredictable period of inching forward in a slowly-moving queue?

Why has Australia (and the USA, etc) realised this while the UK has not? We do have experience of a balance that was closer to UK's, but that balance has shifted as more and more rbts are converted to crossroads (etc), resulting in radical throughput increases. On the other hand, the UK rarely selects the at-grade signalised cross or the diamond motorway interchange; and when they are selected, they are built to a crippled form and scale, thereby obscuring the evidence.

Having said that, Australia obviously appreciates rbts in their appropriate setting, because we still build and use many.

There are varying positions between states here. WA/Perth leans somewhat towards rbts (for a curious reason discussed previously elsewhere), and SA/Adelaide a little. The main reason: WA and SA don't have many motorways, and don't have the heavy traffic of eastern cities. QLD formerly liked rbts too, but the penny dropped years ago, so you won't find them in new high-volume constructions.

In my home state of Victoria, main-road roundabouts are becoming extinct at a rate of about 5/year. A telling fact is that, of all the design aspects in capacity-increase projects, the one most promoted and appreciated is 'replacing the roundabout with signals'. This responds to the fact that, in public consultations prior to design finalisations, the most frequent complaint is 'delays at roundabouts'. This is their experience - and it's the same in the UK, but UK drivers seem prepared to just sit there and cop it.
Roundabout GSJs (whether 2BR or dumbbell) are common in Europe and the US, with massive recent growth in the latter. It would be interesting to know why Australia is going the other way (if it is).

My hypothesis would be that new or upgraded Australian motorways tend more towards higher volumes than Europe and the US due to Australia's relatively sparse network. Higher volumes=more turning capacity needed at service interchanges, i.e., signals rather than roundabouts.

The UK has the somewhat mismatched combination of high volumes+roundabouts, reflecting a cultural commitment to roundabouts, but this is a rather independent issue from Australian practice, which as I say seems anomolous even compared to Europe or the US.
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Re: Coomera Connector, Australia.

Post by Peter Freeman »

jackal wrote: Sat Oct 12, 2024 16:15
Peter Freeman wrote: Fri Oct 04, 2024 00:38
Truvelo wrote: Tue Oct 01, 2024 20:21 Why does Australia hate GSRs?
Wow, that's putting it a bit strongly! I don't think anyone in Australia, whether traffic engineer or motorist, would say that. Most AU drivers of course wouldn't know what a Grade Separated 2-bridge Roundabout is, because they'd hardly ever encounter one - the whole country has only about 20.

Since they're mainly a UK specialty, the more pertinent question is 'why does the UK love them?'.

I think my view on GSRs is well-known to some Sabre readers, and my simple answer to your question is: because they perform poorly relative to diamonds and parclos, except under light traffic load.

It's the old roundabout-versus-signals issue, whether at a motorway service interchange or an at-grade intersection of ordinary roads. A roundabout offers low delay under light load, but fails under duress. Signals handle heavy loading, but make you wait even when there's hardly anyone else in sight. If you always drive off-peak, you're going to love rbts, but at other times, which flavour of waiting do you prefer? Sitting facing a red for a minute or two, with reasonable confidence of quickly proceeding at the end of this cycle, or sitting for an unpredictable period of inching forward in a slowly-moving queue?

Why has Australia (and the USA, etc) realised this while the UK has not? We do have experience of a balance that was closer to UK's, but that balance has shifted as more and more rbts are converted to crossroads (etc), resulting in radical throughput increases. On the other hand, the UK rarely selects the at-grade signalised cross or the diamond motorway interchange; and when they are selected, they are built to a crippled form and scale, thereby obscuring the evidence.

Having said that, Australia obviously appreciates rbts in their appropriate setting, because we still build and use many.

There are varying positions between states here. WA/Perth leans somewhat towards rbts (for a curious reason discussed previously elsewhere), and SA/Adelaide a little. The main reason: WA and SA don't have many motorways, and don't have the heavy traffic of eastern cities. QLD formerly liked rbts too, but the penny dropped years ago, so you won't find them in new high-volume constructions.

In my home state of Victoria, main-road roundabouts are becoming extinct at a rate of about 5/year. A telling fact is that, of all the design aspects in capacity-increase projects, the one most promoted and appreciated is 'replacing the roundabout with signals'. This responds to the fact that, in public consultations prior to design finalisations, the most frequent complaint is 'delays at roundabouts'. This is their experience - and it's the same in the UK, but UK drivers seem prepared to just sit there and cop it.
I assumed Truvelo's 'GSRs' question related to 2BRs, as it was prompted by a post about aborting a proposed 2BR in Queensland, AU. My comments matched that target. They apply to dumbbells to a lesser extent, and I did digress onto at-grade roundabouts, which is where most of Melbourne's extinctions are occurring.

I partly agree with your reply/comments, but -
Roundabout GSJs (whether 2BR or dumbbell) are common in Europe and the US, with massive recent growth in the latter.
In terms of m'way service interchanges and USA's recent RBT growth: yes, but it's more into dumbbells than 2BRs. Owing to their vast existing m'way and interchange inventory, the recent additions have not significantly changed the proportions. Dumbbell proportion in USA is still far below that in UK, and it will never catch up. Also, it's less than in AU, and won't catch up.
It would be interesting to know why Australia is going the other way (if it is).
It's not. We're just shaking off a historical emulation of UK rbt practise that is now perceived as misguided, but are not moving opposite to USA - or EU, AFAIK.

In terms of at-grade roundabouts: that's where USA's recently-acquired and commendable rbt fad is concentrated. They install them by the same criteria as AU. Their proportion will not catch up with UK - and not even with AU, as we already have many.
My hypothesis would be that new or upgraded Australian motorways tend more towards higher volumes than Europe and the US due to Australia's relatively sparse network. Higher volumes=more turning capacity needed at service interchanges, i.e., signals rather than roundabouts.
Indeed, it's higher traffic volumes that weigh against RBTs.

Regarding AU's motorway network being 'sparse', a distinction needs to be made between urban and rural motorways. UK, Europe and USA have far more rural motorways than AU, and they are busier. Our long-distance rural motorways have ridiculously low AADTs (15,000 halfway between Melbourne and Sydney would only rate an S2 in England), and mainly get away with unsignalised diamonds and dumbbells. However, AU's (and USA's) cities have denser internal coverage, by m'ways and capacious at-grades, than UK. So, not sparse really.
The UK has the somewhat mismatched combination of high volumes+roundabouts, reflecting a cultural commitment to roundabouts, but this is a rather independent issue from Australian practice, which as I say seems anomolous even compared to Europe or the US.
I regard AU practise as roughly in line with USA's. If I had to use a word to describe our practises, I wouldn't say anomolous. My adjectives might be Pragmatic, Receptive, Progressive, and Innovative.

'A cultural commitment to' is of course a creative euphemism for 'an inexplicable obsession with'.
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Re: Coomera Connector, Australia.

Post by jackal »

The anomoly was Australia's apparent aversion to building roundabouts at grade-separated junctions, as here for instance:
Another clue is that, 5 km south-east down N.B. Road, there is a roundabout future-proofed for flyover addition. Of course, GSRs are out in AU, so when that is required, it will be built as a different type of interchange. Let's hope SPUI or DDI.
As I said, this departs from US and European practice, where at least dumbbells (but also 2BRs in some countries like Spain) are completely routine.

So it is, in the first instance, a matter of anomolous practice rather than policy. I.e., even if the US and Australia had similar policies, it could be that circumstances in Aus are such that circumstances supportive of roundabout-based GSJs do not arise as they do in the US. I speculated about a possible reason for that (high Aus volumes).

But I suppose I still have the suspicion that, in a large country like Australia with an active road building programme, there will be sufficient diversity of circumstances that roundabout-favourable circumstances will sometimes arise, so if they are not building roundabout-based GSJs at all, they do not in fact have a similar policy to the US. (I set aside the complication of the US and Aus each having a range of policies in different states.)

So I'm saying that, if Australia does not build roundabout-based GSJs, it has at least an anomolous practice but perhaps also an anomolous policy. (Another possibility is that Aus does still in fact build dumbbells, and you only meant to say 2BRs aren't built now, though used the different, perhaps broader name GSR.)
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Re: Coomera Connector, Australia.

Post by Peter Freeman »

jackal wrote: Mon Oct 14, 2024 10:39 So I'm saying that, if Australia does not build roundabout-based GSJs, it has at least an anomolous practice but perhaps also an anomolous policy. (Another possibility is that Aus does still in fact build dumbbells, and you only meant to say 2BRs aren't built now, though used the different, perhaps broader name GSR.)
I see that I did flippantly say upthread "GSRs are out in AU". That was careless - I meant 2BRs only, not dumbbells. Apologies for the misunderstanding.

To clarify :

1. AU used to build 2BRs, though not many. QLD still has about 7. NSW has a few. One, on (rural) M15 Hunter Expresssway, was built about 10 years ago. One in Sydney on A3 is being converted to DDI. Victoria, I believe, has none. WA/Perth (definitely anomalous!) has 11, some quite recent (as discussed previously in another topic). In NSW and QLD a number of rbts were built with flared approaches as future-proofing towards 2BR *, but virtually none ultimately proceeded - they are being upgraded differently, or left as-is and bypassed.

2. All of AU does build dumbbells, especially on rural m'ways. I consider them appropriate, and preferable to 2BRs. It is notable though that many eventually get converted to signalised (diamonds, etc). This has been especially the case along Brisbane-to-Gold-Coast M1, where traffic growth has been dramatic. Also, in Melbourne's far-eastern suburbs approx 15 years ago, Pakenham Bypass M1 was surprisingly built with five consecutive dumbbells in 20km. One was left incomplete, and when housing growth a few years later required the missing arm to be added, it was completely re-worked to be a large diamond **. Another one of them has just been similarly re-worked. I predict this curious string of dumbbells will disappear over the next decade, as the area transforms from rural to urban.

* Here -
https://www.google.com.au/maps/place/He ... FQAw%3D%3D
and here -
https://www.google.com.au/maps/place/He ... FQAw%3D%3D

** Here -
https://www.google.com.au/maps/place/Pa ... FQAw%3D%3D
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Re: Coomera Connector, Australia.

Post by jackal »

^ Thanks. Just a terminological confusion, then. (In fairness a quick search suggests 2BR is my initialism, based on the full DMRB term, and GSR may be understood by others as you intended.)
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Re: Coomera Connector, Australia.

Post by Peter Freeman »

jackal wrote: Mon Oct 14, 2024 14:54 ^ Thanks. Just a terminological confusion, then. (In fairness a quick search suggests 2BR is my initialism, based on the full DMRB term, and GSR may be understood by others as you intended.)
Yes indeed.
I think you first posted 'two-bridge roundabout' in 2008. Did you really get it out of DMRB?
I first used it 2012 - probably caught it from you.
I coined 'GSR' in 2022, explaining in my post that it meant "grade-separated roundabouts, UK 2-bridge style".
I think you first used the '2BR' abbreviation in 2023.
I've only ever used GSR to mean 2BR, as I regard dumbbells as more akin to diamonds. Arguable I know, so there's certainly scope for confusion, and I'll try to standardise on 2BR now.
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Re: Coomera Connector, Australia.

Post by jackal »

Peter Freeman wrote: Tue Oct 15, 2024 09:41
jackal wrote: Mon Oct 14, 2024 14:54 ^ Thanks. Just a terminological confusion, then. (In fairness a quick search suggests 2BR is my initialism, based on the full DMRB term, and GSR may be understood by others as you intended.)
Yes indeed.
I think you first posted 'two-bridge roundabout' in 2008. Did you really get it out of DMRB?
Yes, it's in the current version (CD 122) at p. 60: https://www.standardsforhighways.co.uk/ ... d218e74ffd It's also in the earlier TD 22/06 and I would guess before that too.
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