When she was 5, a degenerative retinal disease left Claudia Folska blind. As a result, she has an unusual perspective on how we can make cities more pedestrian-friendly. By analyzing the mental maps and walking routes of blind commuters, Folska—who is working on a dual doctorate at the University of Colorado Denver in urban planning and cognitive science—believes she can find ways to create urban landscapes that are easier for everyone to navigate. We asked her how this works.

Wired: How did your blindness lead you to study urban design?

Claudia Folska: My adviser suggested that I study how people without sight navigate cities. Blindness deprives you of the information that people normally rely on when getting around. If you can’t see, then you can’t use street signs or detect obstacles in advance or rely on visual landmarks. How, then, do people without sight find their way in a big city? Why are they not always lost? What are their internal cognitive maps like?

Wired: That’s an interesting question, but how do you study it?

Folska: I asked people without sight to draw maps of how they got from the local light-rail station to their destination. I instructed them to sketch their routes and verbally highlight any landmarks or obstacles along the way. The first thing I learned is that their maps were strikingly similar, regardless of onset of blindness. Although they were walking in a typical urban neighborhood, their paths were full of challenges. There was this one metal pole they called the DNA post, because everyone crashed into it and left behind a bit of their DNA. There was the “burning bush,” which was a badly placed shrub that gave people painful scratches. These might seem like minor details in urban design, but they quickly add up to make even a simple pedestrian route much less functional for everyone.

Wired: Someone with sight might never notice these obstacles.

Folska: Indeed, most people with sight, including designers, planners, and architects, do not notice the minuscule details. Some of the most revealing elements in these maps are the dead zones—empty spaces that are so pedestrian-unfriendly that blind people avoid them entirely. That’s why it’s so important to incorporate this research when designing spaces. If blind people consistently avoid certain streets or intersections—if there are blank spots on their maps—that’s a sign that urban planners need to focus less on cars and transit and more on pedestrians. It’s not just about complying with the Americans With Disabilities Act. Paying attention to the sidewalk can create sustainable cities, neighborhoods that encourage all of us to walk. When our cities are easily navigable for the blind, we will have created a place that is safe and navigable for everyone.