The U.S. Surgeon General on Wednesday proposed a radical idea wrapped in a banal government document, a 72-page "call to action" with 359 tiny-font references: Americans, Vivek Murthy said, should walk more.

We should walk to the grocery store, and to school, and to the bus stop. We should take "walking meetings" at the office and spend more time walking in parks. And, because nearly a third of American adults report living in a neighborhood without a single sidewalk, we should rethink how we design communities so that it's actually possible to walk them.

Maybe this sounds like obvious advice, a health tip right up there with admonitions to eat right and wear sunblock. But for much of the last century, the federal government has backed a different idea — cars running on cheap fuel and fast asphalt should carry us everywhere — that has largely proved incompatible with walking.

"If the Surgeon General had called for people to exercise more, that would be just another predictable announcement," says the University of Virginia's Peter Norton, who has studied the history of transportation. "But he called for walking. That puts him up against a long history of official discouragement of walking."

The federal government subsidized the construction of postwar suburban subdivisions so heavily dependent on the car they had little use for sidewalks. The government paved the highways that enabled people to live there, and kept low the gas taxes that made commuting 30 miles a day affordable. Government engineers came, over time, to think of roads as the domain solely of automobiles — and of pedestrians as an impediment to them.

"Nobody set out to deter waking," Norton says, "but in making driving work almost everywhere, they in effect did the same thing."

Smart Growth America, one of many urban-design and transportation groups toasting the Surgeon General's announcement, interpreted it with this question: What if we labeled subdivisions like we do cigarettes?

"This product may be hazardous to your health."

The "call to action," a rare science-based edict meant to shape national discussion on major public health threats, implicates America's car culture and "sprawling land use patterns." The paper, though, is a little coy on the main culprit: "Large distances often exist between home, school, work, stores, and other frequently sought destinations," it reads, "and this distance can limit people’s ability to incorporate walking into their everyday activities."

That language makes it sound as if distance itself were to blame and not the decisions we made to create it. Distance, though, was never an accidental byproduct of suburban design; it was the feature that enabled spacious lawns, mass-produced single-family homes and vast shopping malls. As a black-and-white video about the suburb of Lakewood, Calif., put it, people in "the future city as new as tomorrow" loved "the way the homes and streets were laid out so neatly around the super modern shopping centers with acres of free parking!"

These places didn't just promote driving; they precluded walking. You can't walk to work in downtown L.A. from a home in Lakewood (nor can you walk to a bus stop when there isn't one). And you can't walk to the grocery store when there's a cul-de-sac or six-lane arterial that blocks your way.

In a world where walking isn't easy, or necessary, people who still do it seem like odd outliers (Bernie Sanders still walks to work!). And as our culture of walking has changed, so too has the language that we use to talk about it. “Pedestrian,” as an adjective, is now a slight. We talk about distance today as if it were measured in thirty- or fifty-mile-per-hour time: “The grocery store is ten minutes away,” we say, meaning that it takes ten minutes to get there from behind the wheel of a car.

Over time, as most of us ceased to need to walk, we forfeited spaces once used for that purpose, often to accommodate our cars. This happened in many U.S. cities where whole neighborhoods were ripped out to insert highways. But it has also been true at a more intimate scale, as sidewalks were renounced to widen roads, or as buildings were designed to prioritize ground-floor parking garages over window-shopping.

Previous generations of architects used to ornament the exterior of buildings with details meant to be appreciated by people passing on foot. But when everyone moves at the speed of cars, such subtle touches blur together until there’s no point in creating them any more. Builders in the auto age have subscribed to a different idea about pedestrians: that most of us won't walk more than 300 to 400 feet from our parked cars to the front door of any store.

"In the last few decades," Murthy said Wednesday, "we have lost touch with physical activity." This is true in many ways, in school days that no longer include recess, or in jobs that no longer demand physical labor. But it is primarily true in how we've built (or rebuilt) the world around us.

And research is starting to show the health consequences. Communities designed around more compact, walkable street grids — places that have what the Surgeon General calls "connectivity" — have been correlated in research with reduced rates of obesity, high blood pressure and heart disease (they also have fewer fatal car crashes, another public health problem). One study of a million residents in Toronto found that people in less walkable neighborhoods were more likely to develop diabetes.

Of course, the shift from a walkable world to a drive-anywhere one isn't entirely to blame for the fact that nearly one in two Americans now has a chronic disease. But it seems like a smarter strategy to embed exercise in everyday activities — to induce it on the way to the store — than to expect more Americans to go to the gym.

"Today," Murthy said, "we have the opportunity to reclaim the culture of physical activity that we once had."

At a public event announcing the new document, he even conjured walking's historic role in America as a symbol of inclusion, citing Martin Luther King's March on Washington, and the Women's Suffrage Parade of 1913. Walking, in fact, is deeply embedded in American culture: Competitive walking was the NASCAR of the 1870s. Albert Einstein, in a long tradition of writers and thinkers, believed that the mind functions best at 3 mile per hour, the standard pedestrian's pace.

The Surgeon General's new report offers a few specifics on how to revive to this culture, from building new sidewalks, to better lighting and policing streets. And redesigning communities means locating the places people could walk to — jobs, homes, stores, schools — closer together. More powerful than any of these specifics, though, is the simple fact that the federal government just acknowledged — even if it didn't use quite these words — that we need to design lives that have been modeled for decades around driving around our own feet instead.