I grew up in a suburban neighborhood of Atlanta and always found it odd that we waved at our neighbors but rarely knew them. I suspected it was a symptom of the suburbs. But that wasn’t entirely the case; in fact, only 26 percent of Americans say they really know their neighbors. I’ve always wondered — why is that?

I sat down with my husband Jordan, an urban planner (with an urban planning podcast!), for his thoughts on why most of us don’t know our neighbors and what we can do about it.

Most destinations (and people) are not within walking distance.

I tend to feel more connected to a city when I can be independent of a car. I always thought my sense of community from walking was more of a personal preference, but it turns out that living in places that encourage us to walk helps us build trust with one another.

As sociology professor Rebecca Adams has noted, there are a few key conditions necessary for developing friendships: “proximity; repeated, unplanned interactions, and a setting that encourages people to let their guard down.” This can come from seeing the same people at your favorite bar or learning the name of the crossing guard as you drop your kids off at school. When we can regularly walk to things, we allow for organic relationships to occur.

Jordan points to two developments from the previous century that play a big role. “In the 1920s, you had both the automobile and the first single-use zoning codes.” Separating “land uses” such as residential, commercial, and industrial had understandable beginnings but ultimately “served to remove much of the texture from our neighborhoods,” he says. “Combine that with decisions to mandate more space for cars, and you end up with people and destinations spread ever further apart.”

Our homes and neighborhoods aren’t designed to encourage neighborly interactions.

I remember my first apartment after college. I was living in a complex that likely housed some 300 young professionals. I had fantasies of making friends with people “just down the hall.” I never made friends with a single person in my building.

“It may sound quaint, but the front porch or stoop serves the important purpose of putting us in touch with our neighbors — especially in a way that lets us put our guard down. Of course, context also matters: we’ll want to spend more time along streets that are comfortably narrow and low-speed, and we’ll encounter more people walking if there are plenty of accessible destinations for us to walk to. If you’re required to leave your neighborhood to get to everything from work or school to shopping and entertainment, and everything requires a car to get to, that leaves very little time or opportunity for developing relationships with your neighbors.”

We prioritize the car over the person.

It’s also difficult to ignore the impact of cars on the places we call home. Cars did not have to become the central focus of how our cities were planned, but decades of design standards have made car use the default. Jordan notes, “[This evolution] has not been good for human relationships. It has been good for the automobile industry and related industries. […] We can’t design places for maximum car comfort and expect them to function well as places for human interaction.”

He shares that cities can start by removing driving incentives such as parking minimums and allowing denser development and mixing of uses. We can also start changing design standards to create slower streets that prioritize people rather than vehicles. “If readers are interested in going deeper on the human impact of our development decisions, as well as what we can start doing as individuals and local governments in response, a great place to start would be Strong Towns.”