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Slime mold may be better than us at transportation planning

So slime mold, which is a fungus-like single-celled organism, has a tendency to build highly optimized networks across its food sources. In other words, if you scattered a bunch of food on a surface and then dropped in some slime mold, it would naturally create an interconnected web of linked veins across this surface. And this web would be based on the shortest and most efficient paths of travel between the various food sources.

I am mentioning this odd factoid because ten years ago researchers in Tokyo used this naturally occurring phenomenon for the purposes of trying to improve transportation planning. What they did was map out greater Tokyo. They then placed oat flakes (i.e. food) in spots that correspond to the various cities and urban centers that surround the city. Alongside this, they blocked off the areas where transportation networks do not typically run, such as through mountains and into the water. They then dropped in some slime mold, wet the surface, and watched it grow.

What they found was that the resulting network was remarkably similar to Tokyo’s actual rail network. The slime mold had found the most efficient routes, eliminated redundancies, and generally discovered the optimal way in which to connect its food sources. And if you think about it, this is basically what transit networks are supposed to do. They should connect clusters of people in the most efficient way possible.

It has been a decade since this slime mold transportation discovery was first publicized, and it would seem that it hasn’t really caught on as an invaluable planning tool. So I’m going to go out on a limb and suggest that we should take out a map of every major city in the world, plot its population centers, drop down some oat flakes, and then let slime mold tell us all the ways in which we are screwing up and over-politicizing our transportation planning efforts.

Thank you to Angus Knowles for making me aware of this study. Angus writes an occasional newsletter about cities and housing, over here.

Image: LiveScience


  1. Brett Walsh

    Brandon –

    I left Vancouver to set up in Pittsburgh where we are developing some cool projects in the most interesting transitioning neighborhoods of this City.

    There is an opportunity for a new Director of Planning with the newly elected mayor, the first black mayor in the city’s history, and this city needs someone who can bring leadership and make an impact. The city is world class in certain technology fronts but lacking in real estate development talent and urban planning literacy at City Hall.

    Being such a fan of your contributions on urban planning in your blog and everything else development related (and non development related) I thought I would ask you if you had any recommendations for someone who has done excellent work in another city or comes out of development whom you think would be well suited for this role. We need someone new to the city with a strong perspective.

    If you have any specific thoughts it would be appreciated and will get considered by the Mayor.

    Thank you,


    Brett Walsh
    Hullett Properties
    (646) 215 1965

    Sent from my iPhone


  2. Hello Brandon:
    The Tokyo Transportation Study presented is interesting – thank you very much. It is interesting as it is an organic means and method of understanding linkages. It reminded me of some of my studies at university some years ago. At that time Ian McHarg’s Design with Nature was/is considered an important book that describes a similar methodology, although less organic – but more comprehensive. Design with Nature remains a valuable tool and method to this day for many in our industry – check it out.

    Verne Reimer
    Verne Reimer Architecture


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