CTC capitulation?

[benb]

So, I thought this would be quite interesting. There's a guest blog post on the GB Cycling Embassy site by a traffic engineer.
http://www.cycling-embassy.org.uk/blog/2014/03/03/a-view-from-the-drawing-board-turbogate

it is important not to lose sight of the fact that turbo-roundabouts are all about capacity for traffic. Due to the potential for cyclists to be masked by vehicles when crossing multiple lanes, and due to the increase time cyclists need to cross the wider arms, the risks and nuisance posed by motor traffic are greater than at single lane roundabouts. The Dutch prefer cycle routes [that] are grade separated at turbo-roundabouts as a consequence.

(my bold)

 

[Flying Dodo]

That article is wrong in implying the Bedford roundabout will only have painted lines separating the lanes, which isn't the case, but apart from that it doesn't add anything that hasn't been said already. A very pertinent point is right at the end:-

Given these difficulties, a turbo-roundabout with annular cycle tracks wouldn't be my choice of Dutch infrastructure to introduce somewhere not used to it!

And of course this isn't a piece of Dutch infrastructure. But that does go back to the point I raised in connection with the TRL trial roundabout, in that UK drivers just won't be able to deal with something new and radical, and that a proper Dutch style roundabout in the UK with fully segregated cycle lanes where cyclists should have priority will, sadly, end up killing more cyclists.

 

[stowie]

That article is wrong in implying the Bedford roundabout will only have painted lines separating the lanes, which isn't the case, but apart from that it doesn't add anything that hasn't been said already. A very pertinent point is right at the end:-

And of course this isn't a piece of Dutch infrastructure. But that does go back to the point I raised in connection with the TRL trial roundabout, in that UK drivers just won't be able to deal with something new and radical, and that a proper Dutch style roundabout in the UK with fully segregated cycle lanes where cyclists should have priority will, sadly, end up killing more cyclists.

If we cannot trust drivers to deal with anything new then we will need to accept that the current road configurations which are completely geared towards motor traffic is going to remain unaltered. Which begs the question why CTC would bother at all working on new schemes. Also, the turbo roundabout is completely new for UK drivers - are we saying that they will be unable to cope with this? Shared space was new in places like Poynton but drivers seemed to get the idea fairly rapidly.

The issue you are actually saying is that drivers are very used to taking complete priority on most of our road network and cannot be trusted when they need to cede priority. This is learned behaviour and needs to start somewhere. I would contest that councils are making matters worse in this respect as many have a policy of ripping out infrastructure which needs drivers to cede priority (such as zebras) instead of addressing the root cause (drivers not expecting to have to give way to non motor traffic).

The article demonstrates to me that the whole road network configuration including markings is geared solely for motor traffic. The debacle that would have to be implemented to allow cyclists priority on the roundabouts shows that. In practice many cyclists will come off onto the shared pavement and cycle across the zebras assuming they have priority because they won't be reading the minutiae of the highway beforehand. Maybe we should take what is familiar to drivers (zebra crossings) and adapt to also give cyclists priority but in a way that retains familiarity to drivers? But then I guess we are up against transport planners who have spent their careers adhering to rules that prioritise drivers and are inherently conservative because any "confusing" markings will be blamed for accidents as opposed to the fact that road users should take more care.

 

[stowie]

No it's not. There are other versions of turbo roundabouts in the UK and there have been for years. I can think of two on the A5 at Shrewsbury alone. Plus one in Cambridge and another on the A505/A1M junction...

Really? Because I have used these junctions and none are like the Bedford proposal. Unless I am mistaken, the roundabouts you mention are very dissimilar in design. They are fast, large roundabout with slip roads for traffic taking the left turn. There are no dividers on the roundabout itself and indeed if you want to go left without using the slip road you can. None of these roundabout have the turbo roundabout segregation of lanes on the roundabout. This design is completely new to the UK. Or at least Bedford council certainly think so as it says this on their literature.

 

[GrumpyGregry]

Horsham's town centre 20-mph zone was the first in the country. It was hailed as a model for others to follow. It was a radical alteration not far short of Poynton.

Drivers got used to it.

Time passed.

Drivers got used to it so much they now drive through it at 40mph.

 

[totallyfixed]

I am thoroughly sick of hearing how "it will never work in the UK". The reason it is so much more difficult than elsewhere in Europe, is that in the UK the government kowtows to the motoring lobby and therefore will not introduce traffic laws that support infrastructure changes. When we do implement something new it is only in a few places in the country as a "trial", never mind that it has been tried and tested elsewhere in Europe and works perfectly well, this sets it up to fail because drivers will never encounter it enough to get used to it and of course it will then be deemed a failure, terrific.

 

[GrumpyGregry]

Is that a reason not to have it at all though?

A good question.

Just building it / having it isn't enough. If folk can drive through a piece of road infrastructure in a way contrary to the designers intent because the as-built infrastructure allows them to, e.g. painted lane lines rather than hard kerbs to create lanes, then they will. Repeatedly. As a result of their doing so other more vulnerable users of that shared space will modify their behaviour in ways the designers didn't intend either. This will include cyclists riding on the pavement, folk simply staying away in droves, or using a tin box themselves.

We need to build shared spaces in our towns that actively, and permanently, deter people from driving, that inconvenience the motorists and take away their speed advantage, and which make them think twice about using their cars, and are spaces where the rules around intended driver behaviour are enforced aggressively. We should not create spaces which inconvenience those who rely on muscle power alone, which prioritise a driver's "right of way" over that of pedestrians, and which deploy optimism and paint as a means of policing driver behaviour.

 

[GrumpyGregry]

I am thoroughly sick of hearing how "it will never work in the UK". The reason it is so much more difficult than elsewhere in Europe, is that in the UK the government kowtows to the motoring lobby and therefore will not introduce traffic laws that support infrastructure changes. When we do implement something new it is only in a few places in the country as a "trial", never mind that it has been tried and tested elsewhere in Europe and works perfectly well, this sets it up to fail because drivers will never encounter it enough to get used to it and of course it will then be deemed a failure, terrific.

^This.

Simply put; the UK public love their cars, and all the illusory dreams of car ownership, more than they love other people's children.

A few thousand deaths a year on a roads? Just the acceptable price of doing business.

 

[totallyfixed]

Going slightly off topic but bear with me as it is relevant, I was driving back from the Air Ambulance ride in Coventry a few weeks ago and entered one stretch of dual carriageway that had a clearly marked 40 mph limit. This DC also had speed cameras on it but on this day someone in authority had deemed it necessary to put extra signs out saying "speed cameras out of action". Why?? Anyway, so there I am doing no more than the speed limit while everyone else was doing 60 or 70 mph, and I do mean everyone else, I was the only one obeying the law. I found this immensely depressing, the only conclusion I can draw is that unless the law is present or the consequences are sufficiently severe, the average UK motorist will ignore anything that might slow them down.
I have just depressed myself all over again.

 

[jonesy]

The fundamental differences between standard UK roundabouts and the turbo roundabout are physical separation between the lanes and the 'continental' geometry. What you are describing is a standard UK roundabout with spiral lane markings. However, I would agree that the basic principles of how a driver navigates the turbo roundabout are the same- there are no fundamental changes in priority to consider (as is the case with the Dutch roundabout with the priory orbital cycle lane being trialled by TfL) so in that respect it is presenting fewer challenges for implementation.

 

[jonesy]

So, I thought this would be quite interesting. There's a guest blog post on the GB Cycling Embassy site by a traffic engineer.
http://www.cycling-embassy.org.uk/blog/2014/03/03/a-view-from-the-drawing-board-turbogate
(my bold)

Ok, managed to have a proper read of this. Some points I agree with, however the attacks on the designers: "fraud', "bullshit" etc rather detract from the professional objectivity that the website is clearly trying to claim through inclusion of this blog. And, of course, alternative opinions from traffic engineers are available...

Flying Dodo has already picked up on one important error- the author is wrong on physical separation, suggesting he hasn't got enough information to make a proper assessment of the scheme. He has also misunderstood the point made in the SWOV factsheet about capacity of turbo roundabouts compared with other roundabouts: this is comparison between different types of Dutch geometry roundabouts, not between a Dutch turbo and standard UK two lane roundabout. As I've explained previously, Dutch roundabouts have a tighter geometry, which reduces speed but also reduces capacity. Adding the turbo lanes reduces some of that lost capacity certainly, but there is nothing in the reference cited to suggest that a turbo roundabout with tight (continental) geometry, as proposed for Bedford will offer greater capacity than a two lane UK roundabout optimised for capacity. If capacity for motor vehicles really was the primary objective of the designers then they'd go for a high capacity design based on UK geometry, which isn't what is proposed.

Note also that the author is linking together two quite separate arguments- the merits or otherwise of the turbo design, and the case for introducing Dutch style roundabouts with priority orbital cycle lanes. Even if the turbo proves not to be a suitable design (and I accept that may be the outcome), it still doesn't follow that the latter type is the right solution. Bear in mind that even if the Netherlands there is still a debate on giving cyclists priority on orbital roundabouts (this is clear in the SWOV leaflet cited by the blog); that there are different approaches to roundabout design within the Netherlands, that they generally don't use roundabouts as much as the UK does anyway, still preferring signalised junctions in urban areas, and that there are different priority rules there, so drivers are used to having to give way to cyclists when then turn in and out of side roads. Not to mention different liability rules.

https://www.swov.nl/rapport/Factsheets/UK/FS_Roundabouts.pdf
"There is no consensus about the priority regulations for cyclists on roundabouts with separate bicycle
tracks. CROW recommends priority for cyclists on urban roundabouts, but no priority on rural
roundabouts. However, from a road safety perspective cyclists should have no priority on urban
roundabouts either. "

Given that TfL has been trialling one particular design off-street, with a view to progressing to on-street trials, why would you expect any other authority to wade in and implement one without waiting to see what the outcome of these trials will be?

 

[Pete Owens]

Says who?

1. Drivers: Its bleedin obvious to anyone who has ever driven a car that you need to slow down for bends - and the tighter the bend the more you need to slow down.
2. Dutch Highway Engineers: The empirical research the Dutch did after they converted the first 100 or so roundabouts. The idea was to improve safety by reducing speeds - speeds did reduce resulting in a 70% reduction in crashes - so they rolled it out to convert all 2-lane roundabouts.
3. 'O' level physics - The coefficient of friction of rubber on tarmac limits the speed you can drive round a bend without skidding.

In theory there may be a reduction, or there may be in practice - but it will be time limited once drivers get used to the roundabout.

Its not a matter of getting used to it it is a matter of physical limitations.

And we don't have those already in the UK?

No. This is a first.

The reality is that the reason that Dutch roundabouts appear to be safer is:

• Dutch driver are more likely to be cyclists themselves.
• How to drive around cyclists is a big part of driver training and testing in the Netherlands
• Cyclists tend not to be routed around roundabouts in the Netherlands - there's been a programme of providing alternative routes for cyclists
• The presumption of liability makes drivers more mindful of what they're doing.

Points 1, 2, 4 are valid - but it is hard to see how any safety scheme in the UK would address this (other than requiring Dutch citizenship as a condition of holding a UK driving licence).
Point 3 is not the case - all the evidence points to cycle tracks increasing the danger at junctions.

And the argument is not just that Dutch roundabouts perform better than UK ones (precisely because they are designed to restrict speeds while ours are intended to maximise them) It is that applying turbo geometry vastly improved the safety of what were already relatively safe roundabouts - they already had all the features you list before they were converted - and already had some of the geometrical features such as perpendicular approaches and exits. If they can reduce crashes on Dutch roundabouts by 70% we can expect an even greater improvement by converting UK ones.

Care to provide some links to the empirical evidence, which supports your assertion?

Perhaps when you provide some supporting your opinion.

You appear to be confusing your opinion with fact...

OK here is a tutorial from a numerate biker explaining how tight bends limit vehicle speed:
http://www.stevemunden.com/leanangle.html

 

[dellzeqq]

OK here is a tutorial from a numerate biker explaining how tight bends limit vehicle speed:
http://www.stevemunden.com/leanangle.html

Fine. But in my neck of the woods cyclists are killed by vehicles dong fifteen miles an hour or less while turning.

And all roundabouts are crap. FACT.

 

[totallyfixed]

What of course is needed is a method of changing direction on a bike at busy major and relatively minor 4 or 5 way junctions that does not slow you down much while at the same time not bringing you into any sort of conflict with a vehicle.
It is called a roundabout. Netherlands style, never felt safer. To have priority and respect from motor vehicles is quite something. I don't particularly care if it takes away your "right" to mix it with traffic, cyclists are getting injured and sometimes dying on UK roundabouts, the solution does not include faffing around with compromises and half measures as is this governments wont.
Either go the whole hog or don't bother, everywhere.

 

[jonesy]

Fine. But in my neck of the woods cyclists are killed by vehicles dong fifteen miles an hour or less while turning.

And all roundabouts are crap. FACT.

It's about position as well as speed- placing turning vehicles at right angles to circulating traffic to minimise the risk of cyclists being in blindspots.