December 05, 2006

Traffic islands

A fine road until Coventry council built a centre island:

Traffic island

Centre islands are a major and growing problem for cyclists . It’s become fashionable for councils to construct them to serve as either pedestrian refuges or traffic calming measures.

The idea that central islands make much difference to traffic speeds has been brought into question by a review of traffic calming conducted by the Institute for Transport Studies at Leeds University which indicated that narrowing traffic lanes has little impact on traffic speeds.

As far as the impact on cycling is concerned, an investigation into drivers’ perceptions of cyclists was made by the Transport Research Laboratory under commission from The Department for Transport. To quote the Executive Summary:

Increasing the amount of cycling and improving the safety of cyclists are key aims of the Government’s transport strategy, as set out in the White Paper ‘A New Deal for Transport – Better for Everyone’ (DETR, 1998). Previous research has shown that one of the main deterrents to cycling is a fear of traffic, often attributed to the attitudes and behaviour of drivers [...]

On the basis of this research, a number of recommendations may be made relating to highway design [...]

* physical road features that force cyclists and drivers into close proximity should be avoided, or where this is unavoidable, motor vehicle speeds at such locations should be reduced;

* highway designs that deliberately require cyclists to obstruct traffic in order to produce a traffic calming effect should be avoided as they are likely to cause particular frustration to drivers;

For the whole report (reference TRL549), click here and “buy” the pdf version of the report (it’s free).

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  1. I am very surprised that George can complain about the council building central islands because of the adverse effect that they have on cyclists. These islands are there to protect pedestrians, a much more vulnerable (and populous) group than cyclists.

    How exactly does this central islands benefit pedestrians? The island is too small.

    Where we are referring to refuges, as opposed to islands, I understand that the pedestrians’ lobby prefers zebra crossings to uncontrolled arrangements. But zebra crossings do imply that motorists would have to give way to pedestrians and so councils can’t put them in.

    You can judge the typical reaction of councils with regard to pedestrians by considering the absence of pedestrian phases where the Kenilworth Road crosses Gibbet Hill and the A45. Motorists must not be delayed!

    05 Dec 2006, 22:50

  2. Robert O'Toole

    For a particularly lethal example, see the island on the Coventry-Kenilworth Road just before Common Lane (heading into Kenilworth). The speed limit on this road is 40mph. I would guess that vehicles travel at an average of 50mph, as it is just at the end of a 50mph zone, and they rarely slow down. It is on a busy bus route. I plan to measure the width that it makes available. It looks as if it is barely wide enough to fit a car and a bike, and certainly not wide enough for a bus and a bike.

    Sadly, for a while someone was putting flowers onto the traffic light on the island. So I guess that there has already been a fatality.

    If you are using this route, which is beyond the cycle path, be extra-cautious.

    06 Dec 2006, 10:34

  3. Steve Rumsby

    I do use this route quite frequently, travelling from Kenilworth to Coventry. You are right, it is narrow, but I’m not sure it is significantly narrower than any other stretch of road with a pedestrian refuge. This is a prime example of a situation where Cyclecraft would recommend riding in the primary position, i.e. in the middle of the lane, to actively prevent following motorists from trying to overtake. And you need to move over some way before the refuge rather than just before it, otherwise a motorist might start an overtaking manoeuver before you move over. If there isn’t room for a car and a bike to safely pass through, then don’t let it happen!

    06 Dec 2006, 13:47

  4. Taking the primary position is making the best of a bad situation.
    But councils should adopt more effective and less anti-cycling means of slowing traffic than road narrowings.
    What about speed cameras?

    06 Dec 2006, 14:05

  5. Steve Rumsby

    Looking at the photograph above, I would expect to be cycling in the primary position pretty much the whole way along that road, not just where the centre island is. Why? To avoid being taken out by the door of one of the parked cars, opened by the occupant without first checking for approaching cyclists. As far as I can see, the presence of the island in that particular situation would make no difference to my road positioning. Road narrowings are just one of many situations in which the primary position is appropriate. Once you are comfortable with it, you just use it when necessary, whatever the situation. Narrowings installed for traffic calming reasons, whether they work or not, are just another obstacle to contend with. I don’t find them at all irritating.

    Of course, if they don’t work then it would be better if they weren’t there!

    And if there’s evidence that they cause an increase in car/cycle accidents then that needs to be addressed. But cycle training might be the means to address that, rather than removal of the narrowings.

    06 Dec 2006, 14:34

  6. A cyclist riding sufficiently far away from the parked cars to avoid door opening incidents is easily overtaken by motorists, except at the narrowing.
    Now and again on roads like the above (e.g. Gulson Road Coventry), motorists have overtaken me by drving on the right side of the island.

    06 Dec 2006, 15:13

  7. Steve Rumsby

    Now and again on roads like the above (e.g. Gulson Road Coventry), motorists have overtaken me by drving on the right side of the island.

    That’s happened to me twice that I remember, but only when a motorist has realised too late that they weren’t going to be able to fit through on the correct side of the island. Fortunately, nothing was coming the other way either time. But if I hadn’t been riding in the primary position they would have tried to squeeze through instead, I suspect, with potentialy disastrous results. It is precisely events like that that prove that assertive road positioning is the safest option.

    06 Dec 2006, 16:49

  8. I’d certainly agree that in many cases a cyclist needs to take an assertive position in the road.

    Considering only scenarios without parked cars, lane narrowings fall into three categories:

    • Wide. There’s enough space for most motorists to safely pass a cyclist whose wheels are 70cm from the kerb,
    • Narrow. There’s clearly no room for a car to pass a cyclist whose wheels are 70cm from the kerb.
    • Medium. While there’s not enough room for a car to pass a cyclist whose wheels are 2m from the kerb, some motorists will be tempted to overtake a cyclist whose wheels were only 30cm from the kerb.

    Clearly the medium sized gaps are the most dangerous. I understand, as a concession to cyclists, councils are no long putting in medium width narrowings. To tackle these medium sized gaps a cyclist has to move away from the kerb – but what happens when there’s a constant stream of traffic overtaking the cyclist? How can he/she find a gap?

    With both narrow and medium width narrowings, motorists perceive that the cyclist is getting in their way – after all when there isn’t a cyclist around the motorist can proceed without hinderance. Hence the call for cycle “facilities” to be made compulsory.

    07 Dec 2006, 09:44

  9. Steve Rumsby

    what happens when there’s a constant stream of traffic overtaking the cyclist? How can he/she find a gap?

    By planning ahead. If you are cycling in something approximating the secondary position anyway (i.e. 0.5-0.7m from the kerb), then moving out slowly starting someway back from the narrowing should be no problem. The constant stream of overtaking traffic will have to move further out to overtake and eventually they’ll get the hint. I’ve never consciously thought about how far away I start doing this, but I guess it is about 100m or so?

    I depends a lot on other factors. If I’m moving quickly (20mph+) then I tend to be further out anyway and don’t really have to move at all. This is the case with the example in Kenilworth that Rob mentioned. I encounter this travelling out of Kenilworth rather than in, and the approach is downhill so I get a nice run at it and I’m usually doing 25+mph at that point. At that speed I’m cycling in the middle of the lane anyway!

    I regularly perform a similar “moving out” manoeuver in a different context – getting in the middle lane of a three lane roundabout in order to go straight on. This is the roundabout at the main University entrance, approached from the Westwood Heath Road direction. When there’s a steady stream of traffic approaching that roundabout, as there usually is, I have to indicate right to stop people overtaking me while I move out. You have to do this early enough that if the car immediately behind decides to overtake anyway, you still have time. Planning ahead, again.

    It is all about planning ahead, being aware of what’s around, and especially behind, you, and being confident enough to claim your space on the road.

    07 Dec 2006, 10:46

  10. Tim Sinclair

    I find all of this comment fascinating. Could it be that cycling in England, where the roads are very narrow, is simply not practical? I cycled in New Zealand from the age of 5 to 21 (no accidents – the roads are wide). Having lived here 11 years I wouldn’t even consider cycling. I take my hat off to you all, but I would not contemplate it myself.

    07 Dec 2006, 12:09

  11. Could it be that cycling in England, where the roads are very narrow, is simply not practical?

    Well I cycle 4000 miles a year so it certainly is practical. But there’s plenty that could be done to make it more attractive. One of the problems is councils narrowing the traffic lanes.

    On a slightly different point, I’d suggest that whereever a solid white line is put on a road with only one lane in a direction, that lane should be wide enough to ensure that, without crossing the solid line, a motorist could overtake a cyclist with adequate clearance.

    07 Dec 2006, 19:42

  12. Robert O'Toole

    Perhaps the problem most often lies with incompetent drivers. I was once following a friend along Gibbet Hill Road. I was on my motorcycle, he on a bicycle doing nearly 30mph (!). He’s a proper cyclist, lycra etc. There was a car in front of me. As the cyclist approached one of the traffic islands, the driver decided to have a go at overtaking. Clearly she hadn’t actually noticed the island. She got half way past him, realised she wasn’t going to make it, and so started swerving in towards him. It was horrible to see. At the last moment she braked hard and somehow managed to miss both the cyclist and the traffic island. There may have been space to go past (just), but she just didn’t have the skill, intelligence or foresight to do it safely.

    My conclusion from this, and from many other incidents that I have seen, is that road design is imperfect and often a compromise. If all drivers were of a high enough standard (and that would mean making the test as hard as the motorcycle test) this would not be a problem. However, the standard of driving is so poor that every flaw in road design is a lethal threat.

    What can be done about the standard of driving? I have some simple ideas for the University.

    08 Dec 2006, 16:32

  13. I put that sort of incident down to drivers assuming that all cyslist travel rather slowly.
    The problem would disappear if there were more fast cyclists about, as motorsits would get used to them.
    Not that I’m suggesting that existing slower cyslists should speed up, there should be more of all types of cyslists – which would make the roads safer for all types of cyclists.

    08 Dec 2006, 19:08

  14. Steve Rumsby

    I put that sort of incident down to drivers assuming that all cyslist travel rather slowly.

    I agree with that. I’ve lost count of the number of times a motorist has begun to overtake me, only to discover that the left turn they are aiming for is going to arrive before they’ve got past, so they then have to slow down and pull back in behind, apart from the one or two that stay out there clearly expecting me to slow down so they can complete the manoeuver they should never have started. My habit is such situations, I’m afraid, is to keep going so they realise their mistake, unless that puts them in danger of course, in which case I will slow down. Similarly, I have had people turn right out of side roads, heading in the same direction as me, clearly expecting that they’d be able to do this without me catching them up. Often they misjudge and I have to slow down to let them in.

    Cyclists doing more than 10mph are clearly beyond many people’s experiences.

    11 Dec 2006, 10:55

  15. Robert O'Toole

    There’s a perceptual illusion: a large slow moving object is commonly perceived to be travelling faster than a small un-threatening object. That is sometimes why a car driver will pull out into the path of a motorcycle.

    Sometime ago the DVLA were considering adding awareness of this to driver training. The idea being that if a car driver knows that the illusion may mislead them, they will compensate in their judgements. However, I wouldn’t be too hopeful. The driving test is so ridiculously easy, I can’t imagine that it would make a difference.

    To avoid this, make yourself look bigger and brighter, or buy one of these

    11 Dec 2006, 16:48

  16. I favour the assertive road positioning – although I can almost feel the cager’s evil glare: how dare a lowly cyclist hold them, a rich proud handsome car driver up?
    once you’ve made it clear that they’ll simply have to deliberately kill you (rather than just knock you off as they squeeze through) most see sense.

    I completely re. comments on car test vs motorcycle test. I cycle regularly (“proper cyclist, lycra” etc), but sometimes commute on my motorbike. I’ve done a car test and uni minibus test too (so can compare) and often wonder why is the car test so easy? is there some hidden agenda? what really scares me is that there are people driving illegally, without licenses (presumably ‘cause they failed!) and no insurance

    of course there are also bad cyclists (and motorcyclists – I’m probably one of them heh ;)) too but yep mr bliar please can the car test be more rigorous?

    15 Feb 2007, 15:49

  17. Pablo

    Interesting comments. My former housemate and I used to cycle (I still do) to university through the usual path from Earlsdon ( We used to have heated debates about the way we each cycled… him being much more assertive (dangerous from my point of view) than me. Whereas he would insist that cars had to respect him (and rode in the middle of the road… primary position, I guess), I’ve always cycled being careful not to upset car traffic and drivers. We both agreed that most roads in England are designed for cars only, and that there are not enough cycle paths… however, he decided to make his point by forcing car drivers to notice that they had to share the road with bicycles, while I feel I’m always cycling in “the wrong path”: either in roads (built for cars), or pavements (built for pedestrians). Sharing sounds nice, but the two vehicles (cars and bicycles) are simply too different to share the same path (the main difference being speed and acceleration, I guess). So, putting myself in the position of the driver, and knowing how easily car drivers are enraged, I always thought my friend was actually being quite dangerous by cycling mostly in the primary position… in their road (I can see myself getting upset if cars rode on a bicycle lane I used). Of course I drive in the middle when cycling by a centre island (and other particularly narrow spots), but, in general, I cycle no more than 30cm from the kerb, and often stop before going to the middle of the road when there’s traffic. Anyway… a related question: what do people think of those red plastic signs sticking out on the right side of the bicycle? I don’t have one, but I tend to think they are more pedagogical… instead of saying “I could go left and maybe you could pass, but I am going to stay in the middle anyway”, they say “my vehicle is just too wide for you to pass me right now”.

    19 Apr 2007, 11:12

  18. Pablo

    Sorry, this is the link to the map: (still learning how to use my maps in google maps).

    19 Apr 2007, 11:22

  19. Most of the time in built-up areas I ride with my tyres about 60-70 cm away from the kerb, which I understand is the secondary riding position.

    The primary riding position is the centre of the left hand lane – wheels about 2m from the kerb.

    I feel that the secondary riding position is far enough away from the kerb for motorists to notice but allows the motorist to overtake without too much bother. Riding with wheels only 30cm from the kerb is dangerous, motorists will not notice the cyclist or think that he/she is taking the next left. I note that I very rarely get cut-up by left turning motorists (despite cycling nearly 4000 miles a year)

    I ride in the primary position for short stretches such as on roundabouts when not taking the next left.

    19 Apr 2007, 11:40

  20. always thought my friend was actually being quite dangerous by cycling mostly in the primary position in their road

    A lot of cyclists would get upset by the claim that roads belong to motorists. We would point out that people were cycling on roads long before any cars came along.

    When cars first appeared they were very expensive, so there weren’t many around. The numbers grew a lot in the 1930’s, leading to an explosion in road deaths. Then the Second World War drove most cars off the road. The early 1950’s were a hay day for cycling in Britain. There were far more bicycles on the road than cars. But the rapid decline in the price of cars lead many people to buy them, for convenience especially for the longer journey. So many cars on the road made cycling far more unpleasant (As late as 1980 I’d cycle on the Coventry ring road to work in the morning, something I won’t dare today) and drove many people off their bicycles.

    19 Apr 2007, 13:55

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