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The Problem With Walk Score, the Possibilities of Carbon Goggles
Alex Steffen, 31 Jul 08

Walk%20Score.png So, last week the good folks at Walk Score released their rankings of the walkability of U.S. cities. Though it may be difficult for some of our European readers to believe, walking is still a somewhat radical concept in many parts of the U.S., and for that reason alone, these guys are making a real contribution simply by giving us a way to talk about how easy it is to hoof it from one place to another.

But like so many ratings systems, this one is very far from perfect. Walk Score's site admits as much when it says,

We'll be the first to admit that Walk Score is just an approximation of walkability. There are a number of factors that contribute to walkability that are not part of our algorithm:

* Public transit: Good public transit is important for walkable neighborhoods.
* Street width and block length: Narrow streets slow down traffic. Short blocks provide more routes to the same destination and make it easier to take a direct route.
* Street design: Sidewalks and safe crossings are essential to walkability. Appropriate automobile speeds, trees, and other features also help.
* Safety from crime and crashes: How much crime is in the neighborhood? How many traffic accidents are there? Are streets well-lit?
* Pedestrian-friendly community design: Are buildings close to the sidewalk with parking in back? Are destinations clustered together?
* Topography: Hills can make walking difficult, especially if you're carrying groceries.
* Freeways and bodies of water: Freeways can divide neighborhoods. Swimming is harder than walking.
* Weather: In some places it's just too hot or cold to walk regularly.

But these factors are not incidental. They're fundamental.

For Walk Score to be what it aspires to be -- a universal rating of the walkability of U.S. communities -- its current algorithm, which in essence measures population density through the concentration of certain sorts of amenities, won't do.

Walking is an inherently qualitative and sensory experience. Streetscape matters. A lot. Hills, dangerous street crossings, menacing alleys, mean dogs, dead-end streets, rushing traffic: these things can easily make a dense neighborhood pedestrian-hostile. It's telling to me that several of the neighborhoods that rank highly on their list are ones I know well, and ones that many people would find unpleasant to walk around in, especially at rush hour or at night. Not all dense neighborhoods are walkable, and we want to be promoting good design as much as density.

What's more, the claim to predicting car freedom is a bit flimsy, I feel. The main reason is that while essentially all neighborhoods in which it is easy to go car-free are walkable, not all walkable neighborhoods make it easy to ditch the car. Car freedom requires certain kinds of substructures that not all walkable neighborhoods provide -- not just transit, bike paths, shared cars, but less defined things, like easily walkable connections to other neighborhoods, or nearby markets that keep long hours (since you don't have access to a car to drive across town to get something).

Now, obviously, no algorithm is going to make all these qualitative and complex judgments. The obvious answer is to use crowdsourcing. Open up the mapping process and allow people to rate streets and amenities by certain criteria. Make Walk Score a Yelp for good pedestrian experiences. Allow bikers to collaborate. Include transit riders. Encourage the disabled to bring their own perspective to the streetscape (since not all pedestrians in fact walk).

Users might even be given a set of standardized tools to use to think about walkability, perhaps akin to this neighborhood pedestrian-friendliness checklist (PDF).

Of course, in order to really make something like this take off, the Walk Score guys will have to pursue a model of open distribution, and it seems like they are unfortunately thinking more in terms of a closed proprietary system that commercially licenses uses of the algorithm, for instance to realtors. This is an outdated business model, it seems to me, yet another example of sustainability advocates failing to embrace the power of innovative approaches.

A different sort of tool-building approach can be seen in the Carbon Goggles project. The premise here is simple: we increasingly know the carbon footprint of objects. We have virtual reality systems which can model the real world. What if you combined the two?

Carbon Goggles allows you to move through Second Life and see how much climate impact the things you see there (or at least some of them) would have in the real world, based on AMEE, the amazing carbon footprint database of ally Gavin Starks.




There's a lot to love here, and lots to kibbitz about (given the greenhouse emissions of computing, an avatar footprint view would be a cool feature as well), but the fundamentals are informative: a mash-up tool, based on an open data platform (AMEE shares) and a sort-of-open visualization platform (Second Life is taking steps towards openness), that allows us a window into what was previously opaque.


We also live in a time when, for the first time, it can be ecologically cheaper to think than to burn energy. (In the past, for instance, resources were cheap and engineering was expensive -- now the opposite is true, and in some uses where engineering can be automated, it's trending towards free).

Our world is already aswarm with data, and soon we'll be piping it through our lives in great gushing torrents. We have amazing platforms, brilliant protocols for sharing information, great ideas for mashing-up insights. If we get the systems right -- and that must mean, whenever it's useful and possible, that these systems are open -- we can use our newfound ability to understand the flows in our lives to transform the impacts of our lives, while making our lives more interesting and beautiful.

But only if we get it right.

(Thanks to Gabriel Scheer and Jim Purbrick for the information.)

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Hi Alex:

Great post. I agree that metadata about the hidden life of things needs to be open.. and will go further to say it must also be peer reviewed, standards-based and independently verified.

Also, when looking at a world through "carbon goggles" one needs to be wary of carbon tunnel vision and carbon color blindness.

Objects are often parts of larger systems or ensembles.

Sometimes, in the comparison of two objects, an object that appears to have the bigger carbon or toxic footprint (((that being deemed to be the bad thing))) may in fact be part of an ensemble or process that has a smaller carbon or toxic footprint than the ensemble or process that the object with the smaller footprint is part of.

For example, what is the carbon footprint of an email? is it the one instance you see... or does it include the "shadow footprint" that it casts as it propagates across the net?


Don Carli
Senior Research Fellow
The Institute for Sustainable Communication
Chairperson -

BTW: My SL AV (Meme Autopoiesis) has been fiddling with his carbon goggles for the past month and while Meme sees the potential he has yet to get them to work effectively.

Posted by: Don Carli on 1 Aug 08

Thanks for posting on this. I was going to comment on WC's last walkscore post, but I decided that since 1) they already admit its limitations, and 2) it is at least raising the profile of walkability, I was silent. Glad you were not.

I hit on your same idea, so I just wanted to second it - the folks at walkscore don't need to be the ones who run with this. We just need a neighborhood portal, an agglomerator.
As you suggest, actual experiences (like Yelp) could help, but what about photos of that 'nearby park' from Flickr? Crime data from the police dept. website? Car sharing pods from Zipcar... etc. We have so many tools, I feel like we need a new generation of tools to create more 3-dimensional info realities. I don't know how to do this, sadly, but I bet it isn't hard.

Posted by: justus on 2 Aug 08

We're all gonna die due to global warming. Keep up the great work guys. You gotta save the planet. Golly.

Posted by: Bondi on 5 Aug 08

Last week I almost commented that you would be hard pressed to find a pedestrian or bike rider in Reno,NV who agree with the 92/100 score, due to the agressiveness of the drivers here. The neighborhood-pedestrian-friendliness-checklist will be a big help in trying to change things for the better.

Posted by: john on 10 Aug 08



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