Archive for Cycling

The case against bicycle helmet advocacy: a quick guide

Oct 28, 2011 at 08:34 · Filed under Cycling ·Tagged , , , , , ,

Bicycle helmets are tested with vertical drops from a maximum height of about 3m onto flat surfaces (BS/EN 1078:1997). In such testing, helmets definitely help. However, the scientific evidence on helmets & population wide injury rates is far from clear that helmets actually are beneficial.

While amongst cyclists who suffer injury, helmets of themselves do reduce head injuries significantly, they also increase neck and facial injuries, so that there appears to be negligible benefit overall (Accident Analysis & Prevention: … meta-analysis of bicycle helmet efficacy). Study of bicycle injury rates in Australia around the time of introduction of mandatory helmet laws suggests that, though there is a noticeable dip in injury rates around the introduction of the law itself (not necessarily attributable to the helmet itself in my opinion) that injury rates then started increasing again, to the point rates were nearly the same at the end of the study period as before the helmet law, and trending to surpass it! (My Blog: study-shows-australian-cyclist-helmet-law-leads-to-increasing-head-injury-rates). Helmet use also appears to induce risk-compensation behaviour in motor vehicle drivers – they make closer passes (Accident Analysis & Prevention: Drivers overtaking bicyclists…). No doubt the cyclists themselves also are subject to risk compensation. Thus, by wearing a helmet there may be an increased risk of getting into an accident.

There may be further population wide psychological effects caused by a culture of “Must be wearing a helmet to be safe!”. It is sending the message that cycling needs safety equipment, and hence must be dangerous, which surely will put off many – certainly where mandatory helmet use laws are introduced rates of cycling then significantly decrease. The reverse is of course true: the overall health benefits of cycling greatly outweigh the quite tiny risks – risks which are not greatly changed by helmet wearing, the studies appear to say. In other words, by advocating helmet use, one may be harming the rates of cycling by sending the wrong message on safety, and hence harming public health overall.

Further, as cyclist safety on the roads correlates strongly with rates of cycling – more cyclists leads to more awareness & safer roads, and similarly fewer cyclists means less safe roads – this means a culture of helmet use may well lead to increased injury rates amongst cyclists (in addition to the general adverse public health effects of fewer people cycling). This would be very hard to categorically prove or disprove in causal terms, however the Australian experience certainly suggests a correlation, as I think would a comparison of the UK and Netherlands.

Finally, in the Netherlands, one of the safest places for cycling in the world, cyclists almost universally do not wear helmets, including very young cyclists. Thus, we can be quite certain that helmet usage is not a pre-requisite for safe cycling. Indeed, it is in places like the UK and USA, with some of the worst cycling safety in the developed world, where the focus on safety equipment for the cyclist seems to be greatest.

In short, the focus needs to be on those things around the cyclist (e.g. default legal liability to influence motorists’ behaviour, safer road infrastructure, etc) – not what is on cyclists. Focusing on cyclist safety equipment to me seems futile at best, and perhaps even detrimental to the cause of mass, safe cycling, if that’s a cause you believe worthwhile.

NB: Helmet use should always be a personal choice. The issue is complex, the trade-offs may differ greatly in different scenarios – helmets may be very beneficial in some settings, e.g. some kinds of racing. The choice should be your own. However, general advocacy of cycling helmets seems inappropriate and probably harmful, to me.

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Is this rusty bollard safe for bicyclists?

Sep 21, 2011 at 13:58 · Filed under Cycling ·Tagged , , , , , , ,

Glasgow City Council have acted on my previous complaint to them, on the part about a bollard with a strange bit of jagged, rusty metal on top at the access to the quiet side road off the Broomielaw/A814, by having their cycling officer inspect it. The officer has found that it’s safe – sufficiently at least that no action will be taken it seems. I’ve taken photos of it, to see if anyone else might agree with me…

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The new London Road cycle-path surface

Sep 21, 2011 at 13:06 · Filed under Cycling ·Tagged , , , ,

It seems sending letters/emails to Glasgow City Council actually works. They instructed the contractor to fix the brand-new cycle-path on London Rd with the old, broken, road-surface. The end-result however is still a cycle-path with mostly an old & broken road-surface…

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Reducing car/cyclist conflict: Dutch v Glasgow Style

Aug 22, 2011 at 00:39 · Filed under Cycling ·Tagged , , , , , , ,

Recently I sent a letter to GCC with some complaints about NCR75. To their credit, they appear to have acted on at least some of that letter (with thanks to Alison Thewliss for raising my letter with GCC LES) – they seem to clean the previously glass-strewn path a lot more often now, and they may have put up more signs to show which paths are meant to be shared-use.

However, regarding the Clydeport car-park entrance on the Broomielaw and how it interrupts and inconveniences the national cycle route that crosses its entrance with a dropped kerb, their response was:

At the Broomielaw, National Cycle Route 75 is located on the north side of the Casino, using a shared use pedestrian/ cycle track. Drivers exiting the Clydeport car park have poor sightlines, hence the kerbs nearest the wall on the cycle track have not been dropped, thus encouraging cyclists to stay away from this area, where they are harder to see.

Now, bear in mind this is an almost unused car-park – I’ve never seen a car going in or out there, even though I commute past there every morning and evening. The cycle-path there on the other hand is heavily used. Further, the kerb, though lower toward the outside, is still a raised kerb and an impediment to cycling! Never mind the road surface is also broken up to at least one side.

So the message is, when it comes down to the convenience of a large number of cyclists, versus that of a property holding company and its under-utilised, city centre car park for a couple of employees, well the cyclists can more or less go and get stuffed.

Update: Went past the Clydeport car-park later in the day today and it does seem full.

Entrance to the Clydeport car-park on the Broomielaw, with the National Cycle Route 75 crossing it. The cycle-path has a dropped kerb, very inconvenient for cyclists, particularly any carrying luggarge, and any on normal, non-offroad bikes. Note the cyclists having to stand up to negotiate the kerbs, even though they are out from entrance. Still looks like urban mountain-biking, sadly.

Another view of the car park entrance. Note that cars actually have plenty of visibility to this direction. It is only the wall on the other side that is impeding visibility. Note also the broken surface of the road, making the far kerb even harder to negotiate.

It is actually quite possible to engineer minor side-streets and entrances that must cross cycle-paths so that cyclists progress and safety is not  compromised. They manage it all the time in the Netherlands. The line-of-sight issue could be better resolved by modifying the wall, and/or installing a lowish, progressive projection/kerb around the entrance wall to ensure cyclists move further out (indeed, this would be a good idea either way). Further, it should be Clydeports’ responsibility to ensure that its property does not impose undue risks on the passing public. At least, I would hope there is legislation and/or by-laws in place, to that effect.

So how do the dutch do it?

Dutch cycle-lane, with a minor-side-street junction. The junction is engineered to safely allow cyclists on the busier street the right of way over the quieter joining entrances. Note the conspicuous signage to remind drivers of the cycle lane, and note the concrete segregation barriers immediately before the junction, to prevent car drivers from turning in fast and early.

Note how the road is further engineered to slow down any cars before they cross the cycle lane, and so reduce conflicts. The cycle lane is raised up slightly with a smooth gradient, while the roads have a steeper kerb to negotiate, to force them to slow down and further help make them aware of the cycle lane.

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Glasgow city cycling infrastructure, only for mountain bikers?

Aug 21, 2011 at 23:46 · Filed under Cycling ·Tagged , , , , , ,

Glasgow City Council plan over the next few years to build new segregated cycling paths across the city. This is amazingly welcome news, of course. Work is already underway on a segregated path from Saltmarket, down London Rd towards the East End (to the under-construction velodrom perhaps?). Unfortunately, whether through lack of cash or lack of co-ordination and/or sheer institutional inexperience with building cycling infrastructure, the infrastructure that exists often comes with design and maintenance faults. At least, faults that would be immediately obvious to any regular cyclist. Unfortunately, the new segregated paths, though not yet finished, seem to suffer the same problem of some other such existing cycle paths in Glasgow: You need a mountain bike to use them!

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Towergate Insurance and the Death Wish Cyclist

Jul 14, 2011 at 12:31 · Filed under Cycling ·Tagged , , , , , ,

This is a comment I’ve sent to Towergate Insurance about their “Death Wish Cyclist” video, about which they recently put out a press release:

Hi,

I’m writing about your recent press release at:

http://www.prweb.com/releases/truck-insurance/accident-camera/prweb8592980.htm

In the press release you quote the truck firm, who appears to think his driver is completely innocent. This is a view which Towergate Insurance appears to endorse to some degree, as you have put the video on Youtube with the title “Death Wish Cyclist“. As a car driver and regular cyclist, I think it’s worth pointing out that the video shows the truck driver’s behaviour is far from perfect. Regardless of whatever blame may be attached to the cyclist, there are a number of problems with how the truck is being driven:

a) The Highway Code advises that cyclists should be left plenty of room when passed by motorists (rule 163 and 212). The road concerned is single-lane in each direction, and there is oncoming traffic, so the truck driver could not have changed lane. Yet they were still preparing to overtake, and even accelerated to 44mph as part of this. Had they passed the cylist, it would have been far too close and at too high a speed. The lorry driver was not intending to leave any margin of safety, needed in case the cyclist had to weave or move for some reason, e.g. from a mechanical problem or because of potholes. Motorists who close pass cyclists are driving irresponsibly, especially so when done with heavy goods vehicles which are almost to certain to kill cyclists if there is any contact.

b) The road is through Southampton Common and appears to have a 40mph speed limit. Yet the video  shows the driver reaching 44mph as they prepare to overtake. They appear to be committing a quite obvious offence with their aborted overtake, presuming the data from your system is accurate.

c) There is a side junction ahead, which presumably is easily visible given that the cyclist was manoeuvring to take it. The Highway Code rule 167 states “DO NOT overtake where you might come into conflict with other road users. For example: * approaching or at a road junction on either side of the road“. The Highway Code says this precisely because road users are likely to be manoeuvring to leave or enter the road ahead – as the cyclist is.

d) The Highway Code also states that motorists should take extra care around vulnerable road users, such as motorcyclists, cyclists. Further, though it’s impossible to be certain because the camera lens is extremely wide-angle and doesn’t show enough detail, the cyclist looks like they perhaps may be young – a teenager. The highway code specifically advises motorists to be particularly careful around young and inexperienced road users (rule 204).

Road safety requires that we not only avoid making mistakes, but also that we take care to allow for the inevitability that mistakes will sometimes be made by others. On this basis alone, the driving shown by the truck driver was less than perfect. Further, the driving shown appears to directly contravene a number of rules given in the Highway Code, with which all drivers should be familiar. Finally, contingent on the accuracy of your system, the driver may even have been speeding.

All together, it’s very hard to see how this driver is “blameless” for the narrowly averted accident shown in this incident. Without intending to absolve the cyclist in any way of blame for their part, I think it’s important that anyone watching that video should also realise that the driving shown falls far below what is expected of motorists.

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Study shows Australian cyclist helmet law leads to increasing head injury rates

Jun 23, 2011 at 18:21 · Filed under Cycling ·Tagged , , , , , , ,

This is an edited version of a comment I made elsewhere.

A new study has been published recently on the impact on head injury rates of cyclists by the compulsory helmet laws in New South Wales, Australia. This claims there’s a positive effect on injury rates from such helmet laws, even adjusting for the reported fall in cycling rates due to the introduction of the law. This is being reported by some as evidence that compulsory helmet laws work or even that they lead to a 29% drop in head injuries. However, that seems a misleadingly simplistic view of it.

A careful look at the study  shows there appears to be a significant benefit only over a short-period of time, across the few months where the law is passed. While beyond that the helmet law has managed to turn a decreasing head injury rate into an increasing head injury rate (fig 3). This is despite accident rates themselves being somewhat stable (fig 2). Within a year and a half of the law coming in, the head injury rate is almost back to the same level as before! Given the increasing trend, it is likely that not long after the study period head injury rates would have been worse than before!

So what is happening? There is a divergence between the arm injury rate and the leg rate in fig 3. The arm injury rate has increased, mirroring the head injury rate, while the leg rate stays flat – possibly reflecting the stable-ish overall accident rate. This suggests the nature of accidents may have changed.

The study itself notes there are some possible limitations to its findings:

  • Injury rates are seasonal, and they have only very limited amount of data (less than a year) on the pre-law rates.
  • They assumed exposure to potential injuries was identical for head, leg and arms. While this seems a reasonable assumption, as they say, their own data shows this assumption may not be entirely safe.
  •  They have no data on cyclist types or behaviour, so they can’t factor out things like proportionally more cyclists in riskier environments having given up, or cycling in safer environments having increased (e.g. commuter v recreational cycling).

One possibility is risk compensation, that the extra perception of safety from the wearing of helmets leads to drivers and/or cyclists taking on more risks. E.g. a study on the behaviour of motorists when passing cyclists  has shown that motorists pass closer if the cyclist is wearing a helmet. Another possibility is that injury rates just happened co-incidentally to be at a high prior to the law, and that the law has had little causal effect. Further, the very proposal of the law no doubt lead to a lot of media exposure of the issues around cycle safety. That media exposure no doubt had a strong impact on awareness, even prior to the law’s passing – awareness which faded in time after it was all done and dusted. Or some combination thereof.

That means, so far as the study is accurate, that beyond a short-period, the study actually shows an apparent detrimental impact on safety in terms of head injury rates, and only a transient impact on head injury ratios relative to arm and leg injury rates (the metric they relied on to normalise out changes in cycle use).

Wearing a helmet may well protect your head from serious injury if you get into an accident, the problem is that in wearing one, it you may also be more likely to get into an accident and that accident may even be more serious. Which of those is better is a hard question, but it should probably be an individual choice. Interestingly, some of the safest countries for cycling have very low rates of cycle helmet use – almost no-one wears them in the Netherlands, except for serious sports cyclists.

Update: dg01d linked me to this interesting discussion on cycle helmet safety in the BMJ. Also fine-tuned the language in the conclusion on the possible trade-offs in risk.

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Letter to Glasgow City Council about cycle-paths

Jun 7, 2011 at 14:23 · Filed under Cycling ·Tagged , , , , , ,

Dear Sir/Madam,

On monday morning, the 6th of June, while cycling along the cycle-path along the clyde, from Victoria Bridge to the George IV Bridge, I noticed a significant amount of glass near the Victoria Bridge end – no doubt from weekend drinking. The shards were large, and I warned cyclists coming in the opposite direction. Unfortunately, I did not report it to the council myself – I naively presumed someone else would have and/or that the council would clean the cycle path daily. This morning, Tuesday the 6th, the glass at that location had been mashed into finer pieces and spread everywhere (no doubt in part by unfortunate cyclists). My rear tyre was punctured by this glass, and I know at least 2 other cyclists received punctures. This is the 2nd time I’ve had a puncture on that stretch of cycle-path, in only a few months of cycling it (2/3 of all my punctures).

I would ask that you clean this cycle path today. Generally, I would ask you to clean it and all others preferably daily, or failing that on at least the same schedule as the main roads, or failing that to at least on Monday mornings clear the path of the debris from weekend drinkers. Additionally, I intend to recover from you the costs of a new inner tube (£5), tyre (£29) and the labour to have them fitted.

Another maintenance issue is that one of the poles at the entrance of the side-street alongside the Broomielaw, by the Gala Riverboat car-park, has a piece of metal sticking out at the top of it which is likely one of these days to catch and injure a cyclist trying to enter that side-street.

Also, I have some general comments to make about cycle paths in Glasgow City on their design and maintenance.

* It can be very hard to distinguish which paths are dual-use and which are not, due to poor signage and/or very poor cycle-path design.

E.g. the toucan crossing at George IV bridge going west to the Gala Riverboat appears to lead cyclists onto a foot-path – at least it has a raised kerb to the entrance to the car-park which seems to clearly suggest that path is not intended for cycling. However, if it is not meant to be a cycle-path, then the toucan crossing to that path is encouraging cyclists to proceed down it and so commit an offence. On the other hand, if it is still a cycle-path, then why are there raised kerbs along it? Clear signage here, either way, would be useful. Removing the kerbs and making this cycle path continuous would be an idea, if it is a cycle-path. If the kerbs are intended to make cyclists give way to the car-path traffic, I would suggest reversing things and raising the cycle-path so it is level and giving cars a gradient to traverse and give way to a clearly marked cycle/footpath (there are few cars using this car-park in the morning).

If a cycle path is not easy to distinguish, then some cyclists will stick to the general road – to ensure they do not commit the offence of cycling on the pavement. If a cycle path is inconvenient, they will similarly stick to the road.

* Cycle paths away from the road need to be cleaned frequently.

E.g. the path along the Clyde mentioned above is regularly filled with broken glass from beer and Buckfast bottles. It’s particularly bad underneath the foot-bridge over the clyde – drinkers presumably congregate under there for shelter.  It needs frequent cleaning in order to be useful as a cycle-path. If the means do not exist for the council to do this, then the council should installs signs directing cyclists along Clyde St road instead and create a cycle lane on Clyde St road. It should be noted this same cycle-path (National Cycle Route 75) is also terribly glass-filled along many sections further up-river, such as around Dalmarnock and Carmyle. Parts of the cycle lane on Alderman St are quite debris filled, particularly in those parts where there are dividers between the general road and the cycle lane.

If cycle-paths are full of glass, but the roads are not (cars have a cleaning effect & roads seem to be cleaned more regularly), then clearly cyclists will be encouraged to favour roads over cycle-paths.

* Cycle lanes need to have their surface maintained equally as well as the general road surface.

There are many places in Glasgow where the condition of the surface of on-road cycle lanes is terribly poor. Incredibly, in some cases the general road has clearly had some resurfacing work done to it while the cycle lane has NOT – as the road surface is quite different between them (e.g. parts of Kelso St).

Poor cycle lane surfaces cause cyclists to have to cycle out on the general road surface for their comfort, to make progress and for their safety.

* Cycle lanes should be designed to be convenient, without arbitrary sharp turns or deliberately rough surfaces.

Taking just the NCR 75 in the city as an example, there are several places where the cyclist must make sharp turns. E.g. to rejoin it just after Victoria Bridge, the cyclist must make a sharp turn and go over cobble – the gate that would allow the cyclist to avoid the cobbles is always closed. Next, at the relatively modern underpass for the Glasgow Bridge at Bridge St, there is a very sharp turn at each end and a ridiculous requirement for cyclists to dismount. This section could easily have been designed with a progressive bend on and off the underpass, and the underpass could have been made wider. Further along, where it goes under the M8, there are again sharp turns.

Having to scrub hard-gained momentum because of poorly designed facilities is incredibly frustrating for cyclists. The roads alongside NCR75 seem to manage to stay fairly straight along the same course, increasing the attractiveness of the road to some cyclists.

In summary: Capital expenditure on cycling infrastructure can be wasted, if that infrastructure is not maintained at least as well as the roads, discouraging cyclists from using them. Such capital expenditure is further wasted if its very design incorporates inconveniences to the cyclist (be it deliberately, in order to artificially force cyclists to give way to cars, or unintentionally because the designer simply is not a cyclist). Such issues may cause cyclists to ignore the infrastructure and use the general road instead – risking the wrath of the occasional motor-vehicle driver who considers the road to be solely theirs.

I would ask you to continue to invest further in cycling infrastructure, to encourage Glaswegians to take more to their bikes. The benefits of cycling to public health & traffic congestion would make such investment cheap in the long-run.

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