Hamburger/Throughabout Controversy

[NICK 647063]

I think personally they need to be of a decent diameter to be useful….
Of the few I’ve seen most seem to be where a major road crosses say a B road, or like the A66 that meets the A174 but the A174 doesn’t cross…

The closest the A174 gets to the A66 is over a mile, did you mean the A171 perhaps ?

In that case it was possible because wholesale demolition that occurred when the A66 was built meant there was ample space to build a good sized throughabout. The original round about was considerably smaller.

Yes A171 sorry not A174

[Chris5156]

They'd be wise to can the project in favour of replacing the roundabouts with properly designed signalised junctions.

Disagree.

Signalised junctions in this country seem never to be fitted with flow control [*], meaning you get a red light when there is no conflicting traffic, and lengthy cycles which only encourages amber gambling.
* Actually, the purely empirical but very frustrating evidence suggests that an approaching vehicle triggers a red light, not a green.

That's a case for more intelligently programmed signals, not a case against a signalised junction. There are plenty of junctions with flow control and vehicle actuation, but they're not universal unfortunately.

Roundabouts work most of the time - if really busy, peak-only lights can help. If a needs analysis suggests conversion to throughabout, then perhaps the solution is grade-separating? I have yet to see an example of a throughabout/hamburger that really solves the problem.

But in this situation you have roundabouts that aren't working because they're overloaded, where just signalising them evidently won't provide enough capacity (because if it would, that much cheaper option would have been taken), and where there presumably isn't the money to grade separate every roundabout on the A4174. So in that situation, are you saying it's better to have a congested roundabout or a signalised roundabout that doesn't solve the problem, instead of a properly designed signalised junction?

[jackal]

The justification doesn't exist. It's just become a British habit to keep building them. If it was such a good idea, they'd be built elsewhere: good ideas get copied. The basic roundabout was a good idea, so everybody builds them. Traffic signals were a brilliant idea - now used all over the world. A 4-level stack for motorways is a great idea, and is accepted as the gold-standard GSJ. Hamburger a good idea? It doesn't seem to have recruited many believers.

Spain uses them widely. Here's a mad explosion of hamburgers on Madrid's otherwise motorway inner ring road: https://www.google.co.uk/maps/@40.48305 ... 066747,15z

[Peter Freeman]

My first hamburger experience was A580/M6, probably in the 1960s or 70s ... ? I have a vague recollection of thinking back then that it was a good idea! My most recent experience was in 2019, when I encountered this - https://www.google.com.au/maps/place/Ma ... -2.2426305

Treating myself to a day-trip to Chester, to see the Roman remains, etc, I decided to use the Park-n-Ride facility on the Ring Road (park-n-rides near traffic-unfriendly cities are one of my favourite UK things). Heading south on the A41, ready to turn left at what I'd been assuming would be a roundabout, I hit the back of a queue. For 3 or 4 long cycles of the signals, I inched forwards, finally getting through what turned out to be a hamburger. So - park-n-ride, explore city, return on bus, slowly through hamburger, I decided to walk back 200m before getting in my hire car, and observe the traffic (as any true Sabristo would ). Every arm was still backed up, though not quite as bad as earlier. But there was no discernible reason such as roadwork, lane closure, etc. I later saw on GE and maps that there's no shortage of lanes at that location, so I've no idea why it was so useless.

My opinion of hamburgers was thus confirmed. They're just ridiculous.

[WHBM]

Hamburgers are especially dependent on signal settings to avoid lock-ups. Unfortunately this skill seems to be increasingly lost nowadays.

[jnty]

Hamburgers are especially dependent on signal settings to avoid lock-ups. Unfortunately this skill seems to be increasingly lost nowadays.

Yes - it feels as though every care should be taken to either have the 'through' lane free-flowing or basically empty. Unfortunately the traffic models probably rely on filling it to the brim with perfectly yellow-box abiding motorists so we end up with chaos in the real world.

[Micro The Maniac]

So in that situation, are you saying it's better to have a congested roundabout or a signalised roundabout that doesn't solve the problem, instead of a properly designed signalised junction?

A properly designed signalised junction is like a unicorn - except my young daughter believes in unicorns.

I'm saying it is better to have a roundabout that is congested for an hour or so, twice a day, than a signalised junction that is congested 24/7

[BF2142]

In any case, would South Gloucestershire be wise to cancel the remaining five roundabout slicing schemes on the A4174 in the face of possibly poorly-informed local opposition? In my eyes this falls into the same category of driver opposition as 'why build cycle paths when I never see anyone cycling on this 50mph road?'...

They'd be wise to can the project in favour of replacing the roundabouts with properly designed signalised junctions. It would be more intuitive for drivers to have a conventional signalised crossroads than to try signalising a junction that is inherently not suited to it. Signalised roundabouts, throughabouts, hamburgers and bananabouts are a horrible compromise that's best avoided.

There's a hamburger planned for the A30 junction at Loggan's Moor in west Cornwall. Going to be interesting to see how that works on the main line of a busy road.

[Bryn666]

So in that situation, are you saying it's better to have a congested roundabout or a signalised roundabout that doesn't solve the problem, instead of a properly designed signalised junction?

A properly designed signalised junction is like a unicorn - except my young daughter believes in unicorns.

I'm saying it is better to have a roundabout that is congested for an hour or so, twice a day, than a signalised junction that is congested 24/7

Apart from the vast majority signalised junctions are not congested 24/7 because off-peak they have adaptive signal timings to minimise delays. The idea that there are endless queues at signals at 3am is laughable; what you really mean is you don't like having to wait a few seconds for a signal to change?

Roundabouts are never congested for "an hour or so", they either work or they don't. Once they reach high circulatory flows, they stop working and collisions increase as people try and force their way into gaps that don't exist. This is rather basic traffic engineering, and exactly why we have professionals making decisions instead of people who post on message boards claiming 'well designed signal junctions don't exist'.

This is why hamburgers are rubbish and signalised roundabouts are very rarely any use, because they take the worst parts of roundabouts and the worst parts of traffic signals and fuse them together. 99% of hamburgers would be far more efficient as crossroad arrangements or other signal types like CFIs (https://en.wikipedia.org/wiki/Continuou ... tersection) where approaches allow.

[M4Simon]

So the message is to leave the drive-thru hamburgers to McDonald's.

I'll get my coat.

[Peter Freeman]

That's a case for more intelligently programmed signals, not a case against a signalised junction. There are plenty of junctions with flow control and vehicle actuation, but they're not universal unfortunately.

This subject came up a few months ago, in another thread. I was surprised then to read that the UK still uses traffic signals with fixed timings - that is, not vehicle-actuated. I thought that was a decades-old and now-disused technology. I can't imagine any modern installation providing efficient throughput without traffic-sensing loops.

I believe that all signal installations in Australia are fully programmable and vehicle-responsive. Any AU readers: am I wrong?

[Bryn666]

So the message is to leave the drive-thru hamburgers to McDonald's.

I'll get my coat.

Wimpy don't do drive-thrus for this reason.

[Micro The Maniac]

Roundabouts are never congested for "an hour or so", they either work or they don't.

With the greatest of respect, I've already cited several roundabouts that were congested for an hour or so per day, but were free flowing most of the time, but thanks to the marvels of traffic lights, are now queuing all of the time.

what you really mean is you don't like having to wait a few seconds for a signal to change?

Being in a queue of one, two or even more cars, at a red light, without anyone else in view (on the green phases) is not uncommon... equally, being stopped on a red, watching cars deliberately shoot their reds, is equally not uncommon.

And surely, as a claimed professional, you understand that any unnecessary slowing (or stopping) of traffic is inefficient... while my car can accelerate from stationary back to sixty/seventy quite quickly, HGVs are not afforded the same luxury (to 56) and stopping and restarting wastes a lot of fuel.

This is rather basic traffic engineering, and exactly why we have professionals making decisions ... This is why hamburgers are rubbish and signalised roundabouts are very rarely any use...

Aren't those rubbish hamburgers and signalised roundabouts approved/designed/installed by those same decision-making professionals???????? Nuff said.

[DB617]

This is rather basic traffic engineering, and exactly why we have professionals making decisions ... This is why hamburgers are rubbish and signalised roundabouts are very rarely any use...

Aren't those rubbish hamburgers and signalised roundabouts approved/designed/installed by those same decision-making professionals???????? Nuff said.

Though I can't be certain this happened in this case, it's quite possible the design consultant presented several options to the Council committee/decision maker and the throughabout - while perhaps not considered optimal by the consultant - was chosen by the elected representatives. Unfortunately(?) this is how democracy works. Engineers can sell solutions to the local authority, but ultimately, the decision will be made by people with perhaps very little expertise. We have been treated to big examples of this process in the past couple of years - committees of experts advise elected officials, but the officials have to choose who to or who not to listen to.

[Bryn666]

This is rather basic traffic engineering, and exactly why we have professionals making decisions ... This is why hamburgers are rubbish and signalised roundabouts are very rarely any use...

Aren't those rubbish hamburgers and signalised roundabouts approved/designed/installed by those same decision-making professionals???????? Nuff said.

Though I can't be certain this happened in this case, it's quite possible the design consultant presented several options to the Council committee/decision maker and the throughabout - while perhaps not considered optimal by the consultant - was chosen by the elected representatives. Unfortunately(?) this is how democracy works. Engineers can sell solutions to the local authority, but ultimately, the decision will be made by people with perhaps very little expertise. We have been treated to big examples of this process in the past couple of years - committees of experts advise elected officials, but the officials have to choose who to or who not to listen to.

Exactly this, and those elected officials make decisions based off what whinging know-it-alls want rather than what their paid experts tell them will or will not work.

This is why several less scrupulous consultants now just take the money and churn out any old rubbish; because why bother doing a good job when, for example, the councillor equivalent of Micro the Maniac will tell you he knows better anyway?

[Micro The Maniac]

Exactly this, and those elected officials make decisions based off what whinging know-it-alls want rather than what their paid experts tell them will or will not work.

Isn't local democracy such a pain.

[WHBM]

This subject came up a few months ago, in another thread. I was surprised then to read that the UK still uses traffic signals with fixed timings - that is, not vehicle-actuated. I thought that was a decades-old and now-disused technology. I can't imagine any modern installation providing efficient throughput without traffic-sensing loops.

I believe that all signal installations in Australia are fully programmable and vehicle-responsive. Any AU readers: am I wrong?

In London this occurred more recently due to priority given to cyclists, who do not activate the vehicle actuation.

Then where there is a budget of say £100k for a signal installation, the hardware salesman will try to scoop every bit of that for the hardware side. The programming, which used to be bundled but is increasingly not, with a range of chargeable add-ons, then blows the budget, so the minimal programming is bought and it gets installed with the default settings.

I took up a gross inefficient timing with a local authority just outside London, only to be told that the contracted supplier reviews the timings every three years, and you can't have any change within that. Really ? I presume because it would be charged for.

[Peter Freeman]

^ But - are signals installed without road-embedded detectors on each lane of each approach?

[Bryn666]

Exactly this, and those elected officials make decisions based off what whinging know-it-alls want rather than what their paid experts tell them will or will not work.

Isn't local democracy such a pain.

Yes, pity we haven't brought hanging back given the public want it... I can think of a few candidates I'd have shipped off to the gallows straight away.

Oh, maybe that's because it's a stupid idea. You don't do things just because whingers want it doing. We have representative democracy and civil servants to protect the public from its own stupidity.

[jnty]

Thinking about it, the southerly section of Lothian Road in Edinburgh operates as a hamburger together with the streets around it, with West Tollcross acting as the start of a slip lane into the 'roundabout' for northbound traffic.

https://www.sabre-roads.org.uk/maps/ind ... 18&layer=0

There must be similar examples of gyratories arranged like this in cities dating back many years.