15 May 2012

The Choreography of an Urban Intersection

Urban Intersection Choreography
We are in the midst of an interesting little project here at Copenhagenize Consulting. Something we've been planning for a while but only recently got started with. Like everywhere else, the ever-growing urban cycling boom is causing a backlash in Copenhagen. There's a lot of negative press about bicycle users and little happening to reverse that. When the police go out on their Viking raids for a week at a time, ticketing cyclists for trivialities, the press regurgitate all manner of hype about the 'lawlessness' that will surely cause imminent societal decay. Always forgetting to highlight the fact that The 99% ride by the book and have done for 125 years.

So. We thought we'd look at an intersection - an average one - to observe behaviour and chart patterns and numbers. The Choreography of an Urban Intersection.

We chose the intersection outside of our office window. Not only convenient, but also a unique intersection in that it is primarily a transport hub that connects a north-south road with the main east-west ring. On the four corners of the intersection there is only one shop. The other three corners are vacant. This is an intersection that people travel through. There's a supermarket 100 metres farther along, a hospital 50 metres away and the intersection is in one of the most densely-populated neighbourhoods in the country.

We filmed for 12 hours out of the window. From 07:00 to 19:00. In order to digest and observe we have enlisted the help of an anthropologists - Agnete Suhr. She is well into the material and busy marking desire lines, patterns and counting the traffic users.

Choreography of an Urban Intersection
Agnete's notebook. We're quite sure we'll understand what this all means when she is done.

Without revealing any hard facts or observations at this early stage, it is fitting that the very first traffic user to appear when I turned on the camera at 06:54 was a car roaring through a red light at easily 80 km/h. I believe Agnete is about 5 hours into the day at the moment and already the myths of lawless cyclists have been dispelled. It's really quite dull the way that Citizen Cyclists roll in all directions. It's a ballet more than urban jungle warfare.

There are 18.076 cars each day on the crosstown ring and 13.138 on the north-wouth road leading to and from the city centre. On the same routes there are around 8000 and 7700 bicycle uers respectively. So there is loads to observe.

There are two types of bicycle infrastructure that we're keen to chart. One is the classic cycle track that ends in the run up to the intersection, leaving bicycle users to mix with right-turning motor vehicles. The other one features a pulled-back stop line for cars (5 metres) and a stop line for bicycles up by the crosswalk. We've noticed that minor infractions like rolling through the crosswalk on the former type is more frequent than on the type with staggered stop lines. Simply because people feel safer getting ahead of the turning cars.

We'll be looking at cyclist-pedestrian conflicts as well, but there is really little to go after so far. Motorists, however, who buzz through yellow lights and worse, seem to be keen to win the statistic race.

All in all, it's fascinating so far.

Not surprisingly, we're inspired by William Whyte and his work. Not least this legendary film:


Anonymous said...

Why break the long tradition of doing it right , namely the seperation thing, a place for bikes ,a place for cars ,and a place for pedestrians .
Try to make a survey , asking pedesrains if they feel it's ok with bikes on the sidewalk, I can asure you that the answer will not be "looking at cyclist-pedestrian conflicts as well, but there is really little to go after so far"

Chesse Spleen said...

Copenhagen experiences bikelash? What hope does the rest of the world have if even Copenhagen suffers from entrenched motorist entitlement?

kfg said...

"It's a ballet more than urban jungle warfare."

Ballet is rigidly choreographed and practiced to make it all come together without someone getting hurt. Miss your preplanned mark in time and/or space and some frail young thing may be done for.

Traffic, on the other hand, is pseudo-random in nature

I suggest that what you might be seeing is the wheeled version of aikido. The Way of unifying with the harmonious spirit of traffic.

Or, in non-fortune cookiese; The resolution of the physical conflict inherent to traffic patterns without whacking into each other.

uraok said...

this video http://media.theage.com.au/news/national-news/timelapse-australias-busiest-bicycle-intersection-2674095.html is often used in Australia to show how regularly cyclist break traffic rules. Of course the cycling infrastructure in the video will be vastly lacking to what is being filmed in Copenhagen.

Brad in Bergen said...

kfg, to play devil's advocate a bit, I would say ballet is if anything a weak metaphor for the coordination of traffic. Anyone who drives or rides a bike or even walks has also had to practice doing so to avoid being roadkill in a big city. Traffic is choreographed by automatic lights; human controlled signals; automatic sensors in the road and in the brakes in a car; and by countless moments of eye-contact between all manner of users. Then there is the meta-choreography (closer to what happens in ballet, I imagine) of engineers designing and collecting data on the whole thing. That traffic works in spite of its seeming pseudo-randomness is a testament to the extreme complexity of its choreography.

kfg said...

"ballet is if anything a weak metaphor for the coordination of traffic."

Certainly, I was simply suggesting a stronger one.

"Traffic is choreographed by . . ."

Correct, hence its pseudo-random nature. Walkers are far more random in their motions than cyclists, rather closely approximating the behavior of molecules of a fluid or gas, depending on density. Architects have actually used the methods of statistical thermodynamics to optimize flow of people in public spaces. "Molecules" in a shopping corridor experience more "frictional drag" the closer they are to the shop fronts.

Wheeled vehicles, being more restricted in their possible motions and more directed in those motions, behave more like large particles being carried along with the fluid stream, hence the use of the word "arterial" to describe roadways designed to carry large volumes of through traffic.

Smaller roads and streets for local traffic with a high density of traffic control devices act more like veins, traffic control devices being a form of valve.

Marco te Brömmelstroet said...

great minds think a bike.... Last year I did a similar thing in Amsterdam. However, much less time. More videodata is being collected as we speak....Interesting to see similarities/differences !?

See more (in Dutch, but graphs are clear): http://www.cvs-congres.nl/cvspdfdocs/cvs11_097.pdf

Sir Robin said...

@Anonymous: the long tradition of doing it right is not the separation thing, but the mingle thing.

Separation only came after the car. Before horses, cycles and pedestrians just mingled.

There is a quite progressive approach to get back to those principles and present conflicts to stimulate the interaction between people. Everyone drives slower, but traffic goes smoother and there are less accidents. It's called 'shared space'. Look for some good examples online, there's plenty to find. I like that idea a lot. In my opinion, that's the only way to do it right.

Separation causes 'us vs. them' kind of behaviour. I don't think we need that.

Mikael Colville-Andersen said...

Shared space is a quaint idea and works well in quiet residential areas and small towns. Most residential areas in Copenhagen are shared space and have been for a century.

Safe, separted infrastructure is provided on busier streets. As has been the case for over 100 years. The first cycle track in Copenhagen was in 1892, beating the one on Coney Island by a year. As bicycle traffic and car traffic increased in the early days of the 20th Century, separation took hold. Because it saves lives and because it encourages people to ride bicycles.

Mind-boggling that this conversation is even taking place here in 2012 and that I even have to write this.