Tuesday 3 January 2012

Sustainable safety, Dutch and British-style

David Hembrow and Mark Wagenbuur have announced their intention to "call it a day" on their famous and influential cycling blog View from the cycle path, which, perhaps more than any other journal or piece of work published either electronically, or in print, has encouraged supporters of cycling in the English-speaking world to start to think differently about utility cycling, and has spread understanding of how the Dutch have actually achieved the safest cycling environment and highest transport share for cycling in the world.

I can understand why David and Mark should want a rest. Writing an accurate, high-quality blog for a long period is extremely demanding and time-consuming. Their new posts will be much missed, but their archive of posts will continue on-line as an invaluable resource for cycle advocates, transport planners and engineers around the world. Their last post to be written (though not, apparently, last to be published) is one of the best and most important of all. Entitled Campaign for Sustainable Safety, not Strict Liability, it again busts one of the great international myths about the Dutch cycling culture, explaining the true nature of Dutch liability law and its true influence on cycling conditions in the Netherlands (which is slight), before explaining the Dutch policy that needs to be understood and campaigned for elsewhere, the real basis of the Dutch road safety record: Sustainable Safety. I urge you to read it, and to pass it on to all those interested or involved in the area.

I've mentioned Sustainable Safety here before. It's based on five principles, that Wagenbuur goes into in detail in the second part of the article:
  1. Functionality of roads
  2. Homogeneity of mass, speed and direction of road-users
  3. Predictability of road course and road-user behaviour
  4. Forgivingness of the road environment and the road-users
  5. Awareness of the road-user
Of these, the one that perhaps needs most absorbing outside the Netherlands, because it is so foreign to the way things are done on the roads in most other places, is the second principle: that of homogeneity of mass, speed and direction of road-users. In simple physics terms, homogeneity of mass, speed and direction of road-users means that the chances of crashes that have serious consequences are minimised because, in a given space, all the "vehicles" (and that term includes, here, pedestrians) have similar mass, speed and direction, therefore little kinetic energy relative to one another, and they therefore cannot do much damage to one another if they come accidentally into contact. Sustainable Safety, is, in a way, the simple, common-sense acceptance of the facts that humans are fallible, and that accidents do happen, but that it is possible to engineer an environment in which those accidents are rarely disastrous.

The desire for homogeneity of traffic is thus the basis for the Dutch bias towards separating out the classes of road-users, motor vehicles, bikes, and pedestrians (and in some cases buses, trams, lorries, motorcyclists and mopeds) in their own spaces, to minimise the damage they can do to one another in the event of a crash, and, where such separation is not possible, to ensure that no road-users have enough energy (through their speed, energy being proportional to speed squared) to risk serious damage to others. The homogeneity requirement essentially determines what the vast majority of Dutch roadscapes, streetscapes and townscapes actually look like.

But, strangely, straightforward as this all is, there is a huge amount of misunderstanding and misrepresentation of Dutch traffic safety principles in other counties. There is something of a propaganda campaign in the UK, and possibly elsewhere, by some people, to try to convince others that the basis of Dutch road safety is precisely the reverse of what it actually is, that it is actually about mixing up different types of road users as much as possible. Consider this, from the blog of Angela Saini, a science journalist who has just made a programme for BBC Radio 4:
For the last few months I've been asking traffic engineers and scientists whether it's possible to rebuild the streets in a way that might make us safer, happier and generally nicer people. The linchpin of this idea is an increasingly popular (if controversial) concept known as Shared Space, which is a way of designing streets without segregating road users. Essentially, everyone is encouraged to use the same street at the same time... there are no pavements as such. Pioneered in Holland, it seems to be working over there by slowing down drivers and making all road users more aware of each other. And it's since been imported all over the world.
And this is from the BBC webpage on the programme, to be broadcast today Tuesday 3 January at 21:00 and tomorrow, Wednesday 4 January at 15:30:
The early roots of this innovative concept lies in the work of the late Dutch traffic engineer, Hans Monderman. A passionate advocate of shared space, Monderman and colleagues started small - more than twenty years ago, converted an intersection in the northern Dutch province of Friesland from a conventional signal-controlled intersection to a brick-paved street, giving equal priority to cars, people and cycles. The idea was that people would use their own minds in navigating the streets, building their own informal traffic rules. Research has shown that these kinds of shared spaces automatically reduced traffic speed to under 20 mph - the threshold at which the chances of being severely injured in a road accident plummets. This highly counterintuitive approach - increasing risk decreases accidents is finding favour (albeit slowly and not without opposition) all over the world.
Today, Monderman's vision can be experienced throughout his Dutch province of Friesland, no where more so than in Drachten, an unassuming town that until recently was famous only for being the home of the Dutch electronics giant Philips. Drachten's shared space schemes (and those of its near neighbours) now attracts a regular pilgrimage of engineers and planners, from all parts of the world - Australia, Japan, Britain, South Africa, India and even Colombia.
Now this is all a load of cobblers – except perhaps the statement about the "centre of pilgrimage" – insofar as an impression is being given that shared space is quintessentially Dutch, a significant part of Dutch thinking on planning, an expanding movement in the Netherlands, or a thing that the Netherlands is actively exporting. In fact, shared space has been a very limited experiment in the Netherlands that runs contrary to usual Dutch practice, it has not been popular there, and it is not much known or discussed in the Netherlands. Drachten is a small place (population 45,000), and only a small area of the centre of the town has received shared space treatment.  Other Dutch examples of shared space consist of the odd street, square or precinct, set within the normal Dutch mode-segregated street environment. (And by the way, another thing wrong in the quote is that Drachten is not "home" to Philips, Philips' HQ is in Amsterdam).

Interest in Monderman's ideas has come very much from outside the Netherlands, not within. Marttijn Sargentini, the bike cheif in Amsterdam, and thus a very important Dutch traffic planner, far more important than Monderman, told CTC's Cycle magazine (October 2007):
I'd never heard of Hans Monderman or "shared space" until all these foreign visitors came here and kept telling me about them. Here in Amsterdam we are very clear – for safety, for speed, to give an advantage to the bike, we aim to separate wherever possible.
The Dutch are always experimenting with urban design, and shared space has been a minor experiment there that is getting blown out of all proportion by foreigners who are not seeing the wood for the trees, they are not observing basically what normal Dutch street design is about. The answer Angela Saini's opening question is, obviously, "no", it's not possible to rebuild streets in a way to make us generally nicer people – what a silly idea. Sustainable safety is not about making people "nice". People are as people are, they are human, but design can minimise risks by taking their frailties and real behaviours into account.

Shared space in the UK has been mostly promoted by the architect Ben Hamilton-Baillie, who seems to have made it his trademark. According to a BBC news story on shared space in Ashford, Kent, where pedestrians have complained that the new design leaves them feeling exposed when crossing the shared space roads:
Ben Hamilton-Baillie, the architect behind the scheme, said the point of the shared space was so that pedestrians and drivers interacted and negotiated for space and right of way.
He said that although that may not be easy or comfortable for the pedestrian it did appear to work.
"So far it looks as if there has been a significant drop, particularly in more serious accidents, maybe as much as 75%," he said."That doesn't necessarily translate into how people feel when they cross the street, but the reduction in speed has been the most important single element in transforming what was an unattractive concrete collar surrounding Ashford into a civilised part of the town centre itself."
I beg your pardon? Shared space "may not be easy of comfortable for the pedestrian"? I though that it was supposed to benefit pedestrians! I though it was supposed to give them more freedom! I thought that was the whole idea of it, Mr Hamilton-Baillie!

I can't understand what the point of shared space is supposed to be. The benefits claimed for it seem to be illusory, as Hamilton-Baillie's words, if accurately quoted, seem to confirm. What are the actual better outcomes of shared space as opposed to segregation? Hamilton-Bailie here seems to retreat from any idea that shared space should feel pleasant for vulnerable road-users, to a claim about merely reducing casualties, and a claim that what he has created is somehow more "civilised" than what used to exist. I have heard this word used before by a shared space adherent, it is a favourite word of theirs: geographer John Adams used it once in Camden. It is meaningless, an expression of mere personal aesthetic preference or prejudice. How is this Ashford design "civilised"?

If pedestrians feel uncomfortable and unsafe, as they seem to feel in the Ashford shared space, then they will avoid it, and they will avoid crossing the road there (and particularly vulnerable people like the blind, disabled and elderly will avoid crossing the road there), and so casualty figures might well go down. But that's the easiest way to reduce casualties, and the worst: just frighten the vulnerable away, those who are most likely to have accidents, just exclude the non-motorised, not by law, but through intimidation. That seems to be the British version of Sustainable Safety: a kind of quasi-voluntary apartheid.

You see this in UK cycle route engineering as well: you build something so fantastically dangerous that few people on a bike will ever use it, so there cannot be many cycling casualties, because there are few cyclists, and the safety record for cyclists looks good. Something like this, a crazy cycle crossing of a motorway-type road in the Bikeless Borough of Barnet, North London, which has only ever killed one cyclist, and frightened most of the rest of them away. A good safety record: British-style Sustainable Safety in action.


  1. "Here in Amsterdam we are very clear – for safety, for speed, to give an advantage to the bike, we aim to separate wherever possible."

    Interesting... the Dutch experts say word-for-word the exact opposite of the claim that is now frequently made by the likes of Matthew Wright and Gerhard Weiss:

    "The Dutch prinicple is quite clearly ‘mix where possible, segregate where necessary’. Sounds sensible to me, but leaves a lot open to interpretation."


  2. We have one of these on the A27 cycle route between Worthing and Arundel [http://g.co/maps/xfa93], a potentially-useful route for many cyclists, if it had been designed properly (in practice it's just another pavement conversion done very badly).

    Cyclists and pedestrians are expected to cross two lanes in each direction of motor traffic travelling at motorway speeds (70mph+). Every few years someone asks where there are problems for vulnerable road users on the A27, and this crossing is always mentioned.

    But it seems that there's no way to solve this sort of problem in the UK. The current situation is "safe" because almost no-one uses this as a cycle route, so the authorities are happy. Perversely the limited number of cyclists using the route is used as the excuse to do nothing, rather than seen as the obvious warning sign that something is very badly wrong here.

    We still are willing to spend thousands of millions of tax-payers' money to save motorists from having to slow down a little (a motorway-style bypass for the existing Arundel bypass is still apparently a possibility), but our politicians just don't care about people who aren't in motor vehicles.

    We have Unsustainable Danger in the UK, but sadly our leaders appear to be proud of our road "safety" record.

  3. The problem with the UK is that many of our roads can't decide what they are. Is Oxford Street a major route for buses or a world class shopping street? At the moment the former ruins the latter. Sometimes this is historical; a lack of planning control means that many 1930s major roads such as the Kingston Bypass had houses built on them. Sometimes a "route" may be shoved down whatever roads existed beforehand, as with the South Circular.

    The Dutch also seem to lack this obsession with "stacking", which results in narrow lanes that are hard to filter through on a bike merging again afterwards, often in the actual junction.

    This is West Cromwell Road at its junction with Warwick Road. There are three lanes for through traffic and three lanes for right turning traffic, and another three lanes in the other direction.

    If we turn right, this is where we end up. There are now effectively two lanes due to a bus stand, with drivers expected to merge whilst making a 90 degree turn and also needing to take into account the paths of large vehicles that require more room.

    It has been pointed out that the route from Grays Inn Road into York Way is not too dissimilar, with two narrow lanes merging into one wide one on a bend.

    I certainly think that "stacking" can work, but when narrow lanes merge in short spaces road users are put in needless conflict and the extra lanes use valuable road space that could be used for cycle tracks. (West Cromwell Road could probably accommodate a Dutch style cycle track in each direction without reducing the number of lanes, at least at this junction.)

    Another safety innovation is the turbo roundabout, which can be considered as a spiralised roundabout with separating kerbs.

    As far as functionality goes, the Dutch also do a better job. Many suburban through roads here have a parallel service road. In the UK they are very rarely of any function to cyclists because they often divert away from junctions or end abruptly, generally to stop drivers using them to bypass traffic queues on the main carriageway. In the main they are just somewhere to park cars. But in the Dutch example, cyclists can use service roads for continuous through access by continuing on cycle paths whereas drivers may be diverted back onto the main road at certain points.

    On a British road, one may encounter large swathes of hatching, almost the antitheses of stacking. On a Dutch road the extra width would most likely contribute towards a cycle lane or cycle track.

    I think shared space is a good idea if there is plently of space *to* share, ie there is an absolute minimum of larger or faster vehicles that can dominate. Otherwise, dominant vehicular traffic flows are likely to emerge, especially as Britain lacks any general "give way to the left / right" rule as found at unmarked intersections in other countries, and pedestrians will cross the road when there are gaps in the traffic like on a normal road.

    The main UWE campus where I spend most of my term time has a perfect example of what could be considered shared space; but it is only used for access to the accomodation and a disabled car park and access is controlled by a barrier. The main entrance that leads to the bus stops and taxi ranks is a conventional road.

  4. Great post.

    It's worth pointing out that Monderman himself was quite clear that the success of any shared space scheme was dependent upon there being a large number of pedestrians and cyclists dominating the space, and that this necessitated cycle paths outside of the 'shared' areas.

  5. The Shared space thing is going be interesting in Bristol, where Ben H-B has proposed something just round the corner from his house:

    This is an area that we in Bristol Traffic have extensive data on, so there should be some excellent debate, especially as we also have Hembrow's email address

  6. 'Shared Space' like 'segregation' is really just another tool in the bag - not a magical cure-all or all powerful totem, so it's right to see it critically but also right to apply its good bits where we can...
    In Brighton we have a splendid 'shared Space' scheme at New Road which works well because the lack of delineation and choice of materials give pedestrians confidence to linger and to stray and the lack of parking availability frees up space for better uses.
    Crucially, the traffic flow in the area has been managed (by 1 way & prohibited turnings in surrounding streets) to completely remove any value as a through route for motor vehicles, and this is a big part of its success, but the 'shared space' concept which drove the remodelling is certainly the glue that holds the thing together

  7. I think that's the sensible view, Simon. Shared space can be part of a good town centre solution where other measures to eliminate through motor traffic and encourage pedestrian and bike traffic exist. My beef with Hamilton-Baillie is that he doesn't seem to be saying that, he's not mentioning getting rid of traffic, he seems to be saying that stressing pedestrians out is part of the idea. And the Radio 4 programme (which I have now heard) also made no mention of reducing traffic volume. And the Dutch designer who spoke in that (about a town in Friesland) also seemed to say that stressing cyclists (for their own benefit, apparently) was a good thing – with no analysis of what that did to cycling levels.

    As for lack of parking availability, well it sounds as if the Brighton scheme is much better than Exhibition Road, which remains, after the shared space introduction, still one big car park. No sharing of the space under the cars there.

    Christhebull's point about service roads is a good one. These occupy huge areas of our suburbs to merely provide car parking. If only half of that were removed, there would be enough space for cycle tracks.

  8. Simon is spot on. SS as part of an overall scheme can be good but on a through route with loads of parking It's just a joke... As at Exhibition Road.

    I think it gets traction with those who mistakenly think they can reduce crashes without reducing traffic... You can, sort of.... But at the expense of stressing out pedestrians, particularly those with children. How is that an improvement?

    Untill we have leadership with the vision to drive change beyond their term in office, we will get half measures like Exhibition road and Byng place.

  9. Technically speaking Philips registered HQ might be in Amsterdam, but the "home" of Philips is Eindhoven, which is completely the opposite side of the country to Drachten!

  10. I agree with Simon, shared space is just another tool you can use.

    I find it helpful to flip it around. Many rules of the road are there to let motorists go faster and avoid stopping. For example, traffic lights are often synchronised so that motorists get as many green lights as possible. If the lights were removed, motorists would have to slow down at each intersection. Traffic light removal could be used in combination with speed bumps and chicanes to considerably slow down motor traffic.

    So shared space can be used incrementally and there doesn't need to be a purist, all-or-nothing approach.