John Litchfield,
writing in Monday's issue of
The Independentreminds us that we have just missed the first anniversary of the roundabout. Until the Spring of 1907 mainly horse drawn traffic was allowed to proceed around the
Arc de Triomphe in Paris in any direction that seemed appropriate at the time. One hundred years ago it was decreed that henceforth traffic would proceed in an anti-clockwise direction and give way to traffic entering from the right. Now roundabouts are a wonderful invention, if you grow up with them that is. I hear rumour of a roundabout somewhere in the US but I have never seen it, but I have seen many a US friend describe roundabouts in similar terms to the way I remember my three serious encounters with poisonous snakes (a
Black MambaKrait and a
Taipan in that order).
Litchfield correctly establishes that few Parisian drivers really take account of the rules for passage around the Etiole, whose eight lanes may exist in theory but are not visible as such as motorists compete for advantage. In Britain in contrast we have developed a more sophisticated approach to traffic management. The one I know best, and which is pictured below is known as the Magic Roundabout by way of homage to one of the
great television creations of the 70's (along with the
Clangers who were my personal favorite).
This example of the
genre is found 15 miles north of my home in Swindon (the borough of which consider it a
tourist attraction). It is real, and it is a roundabout of roundabouts, each entry has another roundabout. You can enter it and go to the left or the right, there are many options. What you may not know is that this is a major junction - adjacent we have a football ground, a shopping centre and its en route from a major hospital and a motorway exit. What may surprise you is that it hardly ever jams up. I use it in courses as an illustration of a complex system and our ability to synthesis patters.
Firstly the complex system:
The reason that it works is as you enter the system you can see patterns. If there is not much traffic, then you head in that direction; there are barriers that provide some limitations. Overall traffic adjusts, it self regulates rather than being controlled. If you want to see an example of an ordered system then look at the lights! (yes I know its a sculpture but its pretty close to what you see on an multi-highway intersection in the US.
Secondly, pattern entrainment
If you grew up in a country with roundabouts (albeit no magic roundabouts) then you do have a basic set of patterns in your brain that you can adjust and learn. You may enter the first time by cautiously going round to the left (assuming you come from a civilised country that drives on the correct side of the road), but you are able to blend and adjust to the new system. On the other hand if you come from a country with no roundabouts, you may cope with an ordinary one, but with this you will freeze.
There are two other lessons. Firstly the complex approach is lower cost (no traffic lights) and resilient (no power outrage). Secondly this roundabout has evolved. One of the ways they experimented was movable barriers, seeing the impact of different structures in a safe-fail way before they formalised the structure.
There are major lessons here for organisational design, market management and much else.
Comments (6)
and quicker... It's remarkable that a country that makes as much fuss about efficiency as the US is prepared to put up with the switching costs of traffic lights at a large junction. And now, with mini-roundabouts, we've reduced them to a gesture that doesn't even cost much to build.
S.
hmmm. I wonder how much of the UK technical community was seeded by having The Clangers and then Dr Who at just the right time for a generation.
Posted by Steve Freeman | May 24, 2007 11:01 AM
Posted on May 24, 2007 11:01
Hi David.
Having traveled the world and lived in a lot of countries I can attest to the efficiency of the roundabout - especially in the UK but not in Rwanda! In 1994/95 I served as a 'peacekeeper' immediately following the Rwandan genocide. The roundabout system then to was give way to traffic entering the roundabout which meant that all traffic on the roundabout ground to a halt - I can't say if that is still the case. So my observation is there must be some rules that are understood by all for the system to work. (And by the way this proves I read your blog!!)
Regards Graham
Posted by Graham Durant-Law | May 24, 2007 12:05 PM
Posted on May 24, 2007 12:05
Here's a roundabout in Mt. Prospect, IL outside of Chicago. And I think there are some in New Jersey.
Posted by jackvinson![[TypeKey Profile Page]](http://www.cognitive-edge.com/blogs/dave/nav-commenters.gif)
|
May 25, 2007 6:06 AM
Posted on May 25, 2007 06:06
Steve
I find you guilty of retrospective coherence. Dr Who and the Clangers were made by, and for, a new generation of systemising geeks that emerged due to increasing testosterone levels in their mothers wombs during pregnancy. They are surely a symptom not a cause.
You can normally spot them by their extraordinarily long ring fingers see: http://education.guardian.co.uk/sats/story/0,,2086186,00.html
Ron
Posted by Ron Donaldson | May 25, 2007 9:50 AM
Posted on May 25, 2007 09:50
I drive through two roundabouts on my way to work in the morning in Cambridge, Massachusetts, and it's the angriest part of the morning commute (them, not me). I'm lucky enough to have had some training in the ingenious concept of "mini-circles" in Pretoria and Johannesburg, South Africa. Given their "mini"-ness, they actually function more as round speed bumps than anything else, but I guess that's better than nothing.
Posted by Cory Costanzo | May 25, 2007 5:54 PM
Posted on May 25, 2007 17:54
Part of the problem we have in the U.S. with roundabouts is there are some remaining traffic circles, like the one near Chicago cited above, that were built before the Brits figured out how to make them work in 1966. It's so bad that we have to make a linguistic distinction between "modern roundabouts" and "non-conforming traffic circle."
Posted by J Mearlke | May 30, 2007 6:04 PM
Posted on May 30, 2007 18:04