The automobile was one of the most miraculous inventions of the 20th century. It promised freedom, style, and utility. But sometimes, rather than improving our lives technology just makes everything worse. Over the past century cars have filled the air with toxic pollutants and fueled climate change. Cars have stolen public space and made our cities uglier, dirtier, less useful, and more unequal. Cars have caused tens of millions of deaths and injuries. They have wasted our time and our money.

As New York City's transportation commissioner, Janette Sadik-Khan managed the seemingly impossible and transformed the streets of one of the world's greatest, toughest cities into dynamic spaces safe for pedestrians and bikers. Her approach was dramatic and effective: Simply painting a part of the street to make it into a plaza or bus lane not only made the street safer, but it also lessened congestion and increased foot traffic, which improved the bottom line of businesses.

Jeff Speck has dedicated his career to determining what makes cities thrive. And he has boiled it down to one key factor: walkability. The very idea of a modern metropolis evokes visions of bustling sidewalks, vital mass transit, and a vibrant, pedestrian-friendly urban core. But in the typical American city, the car is still king, and downtown is a place that’s easy to drive to but often not worth arriving at. Making walkability happen is relatively easy and cheap; seeing exactly what needs to be done is the trick.

Thirty years after its publication, The Death and Life of Great American Cities was described by The New York Times as "perhaps the most influential single work in the history of town planning....[It] can also be seen in a much larger context. It is first of all a work of literature; the descriptions of street life as a kind of ballet and the bitingly satiric account of traditional planning theory can still be read for pleasure even by those who long ago absorbed and appropriated the book's arguments."

99% Invisible is a big-ideas podcast about small-seeming things, revealing stories baked into the buildings we inhabit, the streets we drive, and the sidewalks we traverse. The show celebrates design and architecture in all of its functional glory and accidental absurdity, with intriguing tales of both designers and the people impacted by their designs.