Based on exhaustive research and interviews with driving experts and traffic officials around the globe, Traffic gets under the hood of the everyday activity of driving to uncover the surprisingly complex web of physical, psychological, and technical factors that explain how traffic works, why we drive the way we do, and what our driving says about us. Vanderbilt examines the perceptual limits and cognitive underpinnings that make us worse drivers than we think we are. He demonstrates why plans to protect pedestrians from cars often lead to more accidents. He shows how roundabouts, which can feel dangerous and chaotic, actually make roads safer—and reduce traffic in the bargain. He uncovers who is more likely to honk at whom, and why. He explains why traffic jams form, outlines the unintended consequences of our quest for safety, and even identifies the most common mistake drivers make in parking lots.