Slate has just started a new series by Tom Vanderbilt called “The Crisis in American Walking: How we got off the pedestrian path.” Vanderbilt observes that it’s odd to see things like “Campaign to Get America Walking” when ambulation is one of the most natural activities for our species. Reliance on cars seems to be the main culprit in the United States’ sad distinction as being the industrialized country where people walk the least. And that’s a shame, Vanderbilt explains, because walking has many health benefits:

Here are just some of the benefits, physical, cognitive and otherwise, that it bestows: Walking six miles a week was associated with a lower risk of Alzheimer’s (and I’m not just talking about walking in the “Walk to End Alzheimers”); walking can help improve your child’s academic performance; make you smarter; reduce depression; lower blood pressure; even raise one’s self-esteem.” And, most important, though perhaps least appreciated in the modern age, walking is the only travel mode that gets you from Point A to Point B on your own steam, with no additional equipment or fuel required, from the wobbly threshold of toddlerhood to the wobbly cusp of senility.

Despite these upsides, in an America enraptured by the cultural prosthesis that is the automobile, walking has become a lost mode, perceived as not a legitimate way to travel but a necessary adjunct to one’s car journey, a hobby, or something that people without cars–those pitiable “vulnerable road users,” as they are called with charitable condescension–do. To decry these facts–to examine, as I will in this series, how Americans might start walking more again– may seem like a hopelessly retrograde, romantic exercise: nostalgia for Thoreau’s woodland ambles. But the need is urgent. The decline of walking has become a full-blown public health nightmare.

The US certainly has a problem with physical inactivity: In 2009, only 51% of the population got 30+ minutes of moderate physical activity five or more days per week, or vigorous activity for 20+ minutes three or more days per week. This is one guideline for adequate physical activity, but evidence is accumulating that even if you hit the gym 3-5 times a week, that may not be enough to offset the health toll of sitting still for several hours each day. One benefit of a lifestyle that includes walking is that it can get you moving multiple times in a single day. Commuting to work by public transportation can give you two walks per weekday, if you have to move between a station and your destination under your own steam. (I just plugged my own commute into Google maps and realize I walk a bit more than 1.5 miles per day going to and from bus stops.)

The thing that seemed to me to be missing from Vanderbilt’s piece (at least so far — there are three more installments to come) is a recognition that walking habits and public attitudes toward pedestrians differ substantially between dense, well-connected areas and areas where it’s hard to get around without a car. Here in DC, the city has invested a lot of time and money in improving pedestrians’ experience, and what I read online suggests many other cities are doing the same. Home rental and sale listings trumpet the location’s high Walk Scores — which reflect the number of destinations (grocery stores, schools, restaurants, parks, etc.) within walking distance — and proximity to public transportation. This doesn’t necessarily mean that drivers are all yielding to pedestrians in crosswalks, but pedestrians are more than just an afterthought to planners.

Pedestrian-friendliness isn’t uniformly distributed; some suburbs do a good job of making sure there are sidewalks and pedestrian-friendly intersection crossings, while some cities have areas that are hazardous to walkers. Overall, though, those living in urbanized areas will find it much easier to incorporate walking into their routines, whether for recreation or to get from one place to the next. It’s worth working toward a future where the infrastructure makes it easy to take a walk.