Background: Understanding more about the unseen side of our responses to visual stimuli offers a powerful new tool for transportation planning. Traditional transportation planning tends to focus on the mobility of vehicles rather than on opportunities to encourage sustainable transport modes, like walking. Methods: Using eye-tracking emulation software, this study measured the unconscious visual responses people have to designs and layouts in new built environments, focusing on what makes streets most walkable. Results: The study found key differences between the way the brain takes in conventional automobile-oriented residential developments versus new urbanist layouts, with the former lacking key fixation points. Conclusion: The study’s discoveries significantly explain why new urbanist layouts promote walking effortlessly and conventional automobile-oriented residential developments cannot.