And this is what the walk scores mean:
Seattle, by the way, is the 6th most walkable city in the US. Top honors go to San Francisco, followed, not unpredictably, by New York, Boston, Chicago and Philadelphia; Washington, DC is seventh and Portland is 10th. More surprising, maybe, is that Long Beach and Los Angeles come in at 8th and 9th respectively, despite the latter's epitomization of car-centric development. And the least walkable city in America? Jacksonville, Florida. (By the way, I have a pet theory that Jacksonville doesn't actually exist.)
* 90–100 = Walkers' Paradise: Most errands can be accomplished on foot and many people get by without owning a car.
* 70–89 = Very Walkable: It's possible to get by without owning a car.
* 50–69 = Somewhat Walkable: Some stores and amenities are within walking distance, but many everyday trips still require a bike, public transportation, or car.
* 25–49 = Car-Dependent: Only a few destinations are within easy walking range. For most errands, driving or public transportation is a must.
* 0–24 = Car-Dependent (Driving Only): Virtually no neighborhood destinations within walking range. You can walk from your house to your car!
The methodology does have one flaw, though. The rankings are based on an average within a city's borders, which introduces an element of arbitrariness. For instance, San Francisco actually has a pretty tiny land area; the urban conurbation extends well beyond its political borders, and almost all of the measured area is part of the urban core. Whereas El Paso, for instance - though it wouldn't be ranked high by any measure - is given an even worse ranking due to the fact that much of the area within its city limits is actually comprised of an uninhabited mountain range, driving down its walkability average. (UPDATE: Oops - turns out I was wrong about this. From Walk Score's methodology page: "We weight the Walk Score of each point by population density so that the walkability rankings reflect where people live and so that neighborhoods/cities do not have lower Walk Scores because of parks, bodies of water, etc." However, using city limits still does introduce some level of arbitrariness, since city limits of older and denser cities, like San Francisco and Boston, tend to be smaller, encompassing only the urban core; whereas a lot of younger Sun Beltish cities, like Houston or, indeed, El Paso, have incorporated suburbs. And that drives the walkability average up for the older, denser cities (which are the most walkable anyway, by and large) and drives it down for the (already less walkable) newer, sprawlier cities. So there you go.)
Still, the maps are great; I think it might be the single best measure of the success of urban communities, simply because it measures the extent to which cities are built for people, rather than for cars - and people are, you know, sort of the raison d'etre of urban environments. Now if only they had maps for cities in other countries - the comparisons would be fascinating.