A bit of a follow-up to last week’s post about the Perne Road roundabout, looking at the potential issues, and what could have been done instead.
This roundabout has now hit the headlines because a child has been injured while cycling on the roundabout, on Wednesday evening. I don’t think it’s massively helpful to leap to conclusions on the basis of one incident, but it’s certainly worth looking at the general design flaws with this roundabout, and the alternative ways in which it could have been designed.
For me, the central problem is that cycling has not being designed for explicitly. Instead, it has been bodged into pedestrian-specific design, and into motor vehicle-specific design, simultaneously. Almost all the potential issues flow from this failure. The roundabout design expects people on bikes to behave like pedestrians, or like cars; something genuine Dutch design would never do.
For a start, the ‘shared use’ paths around the edge are quite obviously footways, on which it is permissible to cycle. They are not cycle tracks, with clearly defined routes. The result is cycling in a pedestrian-specific environment, and this, coupled with a lack of clarity, presents a number of problems.
With ‘shared footways’, drivers will have less certainty over where a cyclist might be heading. Take the scenario below, with the path of a cyclist represented by the blue arrow.
The driver doesn’t know if the cyclist is, or isn’t, going to use the crossing. The cyclist is travelling across an expanse of tarmac, and their intentions aren’t clear. The driver may assume wrongly.
Contrast this with a Dutch roundabout (in Assen) -
And the same is true from the perspective of people cycling. They have more time to assess which direction a driver is taking – staying on the roundabout, or leaving it – and therefore will have more opportunities to cross, more safely. Again, this is without cycle priority -
The Cambridge roundabout does not have this cycle-friendly feature. Because the crossing points are not set back any distance from the roundabout, there’s little time in which to assess which way drivers might be heading. In many instances, it may be too ambiguous to take a chance.
Placing the (pedestrian) crossings at these locations close to the roundabout also means they are blocked by drivers queueing to enter the roundabout, rather than left clear, as on a Dutch roundabout, by setting the crossing points back from the perimeter.
Funnily enough, although I’ve criticised the Poynton scheme, this ‘setting back’ of the crossings has been done correctly there, approximately one car length back from the ’roundabouts’.
This means people can cross behind stationary vehicles, rather than trying to cross in front of a vehicle that might be about to jump into the roundabout.
To compound these issues of uncertainly about where people are going, drivers have to contend with people cycling on the road, and on the footway, simultaneously, as they enter and exit the roundabout, rather than dealing with cyclists at one clear crossing point, on defined paths. This is a point John Stevenson makes here -
Drivers don’t know where cyclists are going to be. Because cyclists can either use the main carriageway or the shared-use, off-carriageway paths, drivers are expected to look for cyclists in a number of places at each arm of the roundabout, instead of just one.
Unnecessary complication has been added by putting people cycling on two different forms of route across the roundabout.
Another issue John identifies – having visited the site – is that a shared-use footway, by definition, involves mixing up pedestrians and cyclists together, rather than separating them, and that can be an uncomfortable experience for pedestrians, particularly in areas with high levels of footway cycling. Again, this problem is not one that should have been created.
What effect might the narrowed carriageway might have on people who continue to cycle on it? John thinks it might make collisions more likely, as people cycling will be closer to motor vehicles (and there also might be a temptation to squeeze through). That said, the geometry has been tightened, which should lead to lower vehicle speeds – so the collisions would probably on balance be less serious. Swings and roundabouts, although it is obviously far too early to make definitive judgements. In any case, a roundabout with this volume of motor traffic shouldn’t – in principle – be designed with the expectation people will be cycling on the carriageway.
Finally, there has been an awful lot of discussion about whether or not a genuine Dutch-inspired roundabout design would offer cyclists priority over motor traffic, or not. To me, that’s not a particularly pressing issue, compared to the overall design problems set out here. A Dutch roundabout with priority would look very similar to a Dutch roundabout without priority. Cyclists would have clear routes, separated from pedestrians – routes which would make it obvious to drivers what they are doing. Likewise the paths that drivers are taking would be clear, and the roundabout would be designed to maximise crossing opportunity. This roundabout achieves none of those outcomes.
My personal inclination – and I’ve been persuaded on this point – is not to offer cyclists priority, for the main reason that it is safer (remember, this is an entirely new kind of treatment for British drivers), and also because the loss of convenience is marginal, if the roundabout is designed properly. We should remember that no Dutch roundabout offered Dutch cyclists priority, at all, until the 1990s, by law. It was only for reasons of convenience – not safety – that his law was changed, and priority was switched in urban areas.
Priorities can be changed easily – bad design can’t.
The Perne Road/Radegund Road roundabout in Cambridge reopened recently – it’s been redesigned with ‘continental’ geometry, and wide shared use paths around the perimeter. This picture from Chris Rand gives you an impression of how it looks (and some of the potential issues).
This redesign was at a cost of £413,000 – £240,000 from the DfT’s ‘Cycle Safety Fund’, £70,000 from the European Bike Friendy Cities Project, and the remainder from Cambridgeshire/Cambridge City Council’s cycling budget.
I’ve been struck by some of the comments from the designer – Alasdair Massie – which can be found here. I’m going to analyse these, in turn.
The geometry is taken from Dutch guidance, although you will see some differences from the classic “Dutch” roundabout. Most significantly there is no segregated cycle track around the perimeter. This was a deliberate decision. We could have provided one, there is sufficient space if other elements were adjusted, but there is no off-carriageway infrastructure to link into and no prospect of providing any in the foreseeable future. [my emphasis]
Here it is stated that the decision not to provide cycle specific provision, away from the carriageway, around this roundabout is deliberate - it could have been provided, but because there isn’t any infrastructure to link to it, there apparently isn’t any point.
I find this slightly boggling. It implies that segregated infrastructure can only ever join up with existing bits of segregated infrastructure, which has slightly disturbing implications for a country that has next to no existing segregated infrastructure.
It’s also, well, complete rubbish. Segregated infrastructure can, and does. join up smoothly with other bits of cycle provision that doesn’t involve separation. Cycle provision in the Netherlands is not made up entirely of segregated provision - it’s made up of a variety of treatments, all of which smoothly transition from one to another, as you cycle along.
So a moment’s reflection shows this kind of assertion to be baseless.
In addition, these kinds of transitions in the Netherlands frequently occur at these kinds of situations. There might be a cycle lane – or even no provision at all – on a link approaching a roundabout, or junction, which then transitions to segregated provision, at the conflict points.
In fact, this kind of arrangement is very, very common, because designing proper separation at junctions is a priority. I’ve frequently been struck by how fairly crap Dutch roads still manage to prioritise physical separation at junctions, because that’s where it is most important. You’ll see it in rural areas too.
So this explanation doesn’t really stack up. Next -
There is a significant amount of pavement cycling at certain times of day, principally by school children. One of our aims was to make it safer for people to cross the roundabout using thefootways, without actively encouraging footway cycling. We also wanted to make it easier to cross on foot, as the previous arrangement involved a 60m detour via a Pelican Crossing, with guardrails to prevent jay walking.
‘A significant amount of pavement’ cycling suggests that on-carriageway traffic levels are too high for people to happily share the carriageway. A proper response would surely involve designing explicitly for these people, creating the segregated provision that it is acknowledged would fit here. Indeed, this has been demonstrated visually.
There are issues with motor vehicle access to the properties to the north east of the roundabout (not insurmountable – it would be relatively easy to provide motor access along, or across, the cycle tracks) and whether the Dutch would provide this kind of design with or without cycle priority across the arms. In either case – no priority, or priority – there would be separation from pedestrians, and clear routes through the junction. The motor traffic levels of around 20,000 vehicles/day (as discussed below) would, under Dutch guidance, still allow priority to be provided (the threshold is 25,000 PCU/day – p.246 Diagram 43).
But instead of creating this high-quality provision, the intention is apparently to make it easier for people to cycle on footways, ‘without actively encouraging’ it. Something of a contradiction.
I designed the work and I cycle across it every day on my way to work. I have to say that I am very pleased with the outcome. The traffic flows more smoothly and calmly; it is much easier to break in and out of the flow on a bike, and having watched Coleridge College empty out on Wednesday afternoon, the off-road provision works fine.
Translation – I’m happy cycling on the roundabout; it works for me. And there’s a footway people can cycle on, for those people who don’t want to mix it with traffic.
There are then some follow-up comments from the designer. Among these is a repeat of the earlier argument that segregation won’t work, because there is no segregation on the approaches.
There are no segregated cycle tracks on the streets leading to the junction, no prospect of any being provided in the foreseeable future. Where roadside cycle tracks exist elsewhere in urban Cambridge they are problematic and unpopular with many people. We used to call the abuse suffered by on-road cyclists the “Milton Rd effect” after a particular roadside cycle track. Where isolated cycle tracks exist at junctions they give drivers an excuse to harass and abuse those people who choose not to suffer the danger, delays and inconvenience of using them –I speak with personal experience.
Creating an isolated, segregated cycle track here would have been detrimental to the design in many ways. I would not have recommended it at THIS junction even if the funds were available.
I’ve already examined why this ‘lack of continuity of segregation’ argument is bogus. Another argument appears here, however – that ‘isolated cycle tracks’ at junctions create harassment from drivers for those people ‘closing not to suffer the danger, delays and inconvenience of using them’.
Note – this argument is coming from someone who has just designed in off-carriageway provision on this very roundabout, that he himself chooses not to use! It’s extraordinary hypocrisy. Surely you should build off-carriageway provision that you yourself would choose to use, before you start complaining about its effect?
However, this follow-up comment is more revealing, in that it shows what I think is the actual motivation for the design.
I have to say that I have been a little taken aback by the venom with which some in the twittersphere have attacked this design. As far as I can understand the anger is ideologically based – we did not provide a segregated peripheral cycle track and so some people hate it on principle.
I am not sure at what stage we abandoned the Hierarchy of Measures in LTN 02/08, but this is NOT a junction where I believe that a segregated cycle track around the outside is either necessary or appropriate. Ours is a TOP of hierarchy solution – it reduces traffic speed, it addresses junction danger, it does so by changing the geometry from the wide, flared, tangential British roundabout geometry to a tight, radial arrangement typically used in the Netherlands.
The absence of a separate cycle track is not due to an oversight, a misunderstanding or due to a lack of funds – although funding would have stopped this project in its tracks, if people had insisted on all or nothing. It was a deliberate design decision, because this was the most appropriate solution for the junction. [my emphasis, again]
Now, I think the Hierarchy of Provision (or Hierarchy of Measures) is a woeful piece of guidance, precisely because it can lead to bodged outcomes like this. To see it being used to justify this kind of design says it all. It’s so open to (mis)interpretation it needs to be jettisoned, and I’m glad to see a growing consensus on this.
Indeed, this is a textbook example of how the Hierarchy of Provision can be misused. For a start – the top measure in the Hierarchy of Provision in LTN 2/08 is actually to reduce motor traffic volume, not ‘speed’. This hasn’t been addressed at this roundabout.
In fact, a roundabout with this kind of layout would actually be appropriate, if the Hierarchy of Provision was properly applied, and motor traffic levels were actually reduced to 6000 or so motor vehicles per day, which is what the CROW manual recommends as the maximum volume for ‘mixed traffic’ (cyclists and motor vehicles sharing the carriageway) on a continental geometry roundabout. With that level of motor traffic, a roundabout designed like this could properly accommodate cycling on the carriageway, for everyone.
But the designer hasn’t done this – he’s employed the Hierarchy of Provision ‘pick and mix’, picking out elements from it like speed reduction, junction layout changes, and off-carriageway provision, blending them all up, and then claiming that the outcome is a ‘top of the hierarchy solution.’ Which is just meaningless guff, because
How on earth does that amount to a ‘top of the hierarchy solution’?
There is then the belligerent insistence that not providing a cycle track is actually ‘the most appropriate solution for the junction’ – apparently in defiance of the fact that significant volumes of motor traffic will still be flowing across it.
There are DfT counts for Perne Road (which runs N-S across the roundabout) – these figures show around 13,000 motor vehicles per day flow along this road. I can’t find figures for an E-W direction, which looks quieter, but this figure of 13,000 vehicles per day corresponds with a quoted figure from Martin Lucas-Smith of 20,000 vehicles using the roundabout, every day (in the comments here).
So this is a busy roundabout, one that – if we really care about making cycling an attractive transport option for anyone – certainly shouldn’t involve people cycling on the carriageway. As already mentioned, it far exceeds the Dutch threshold for ‘mixed traffic’ (i.e. integrating cyclists and motor vehicles) on roundabouts, of 6000 PCU/day (Diagram 42 of the CROW manual, page 246).
I cannot understand how – in this context of continuing high levels of motor traffic – expecting people to share is ‘the most appropriate solution’, especially when the design itself acknowledges that many people don’t want to do this.
Great historical speeches on matters of ambition, put through the Department for Transport Cycle Funding Filter™.
“We welcome change and openness; for we believe that freedom and security go together, that the advance of human liberty can only strengthen the cause of world peace. There is one sign the Soviets can make that would be unmistakable, that would advance dramatically the cause of freedom and peace. General Secretary Gorbachev, if you seek peace, if you seek prosperity for the Soviet Union and eastern Europe, if you seek liberalisation, Mr. Gorbachev, aspire to explore ways of working together with other parties to develop a strategy for tearing down this wall!”
“Its hazards are hostile to us all. Its conquest deserves the best of all mankind, and its opportunity for peaceful cooperation may never come again. But why, some say, the moon? Why choose this as our goal? And they may well ask why climb the highest mountain? Why, 35 years ago, fly the Atlantic? Why does Rice play Texas? We choose to go to the moon. And that’s why my aspiration is to explore ways of potentially getting the funding together by the end of this decade, working with other countries.”
(More suggestions gratefully welcomed)