Here is a narrative that has been playing out over the last several years in any number of American towns: Traffic engineers notice that a particular intersection has a crash problem or is moving traffic inefficiently. After a period of study, the engineers propose a roundabout. The engineers, armed with drawings and PowerPoint slides, visit a community meeting. They try to explain the benefits of their proposed design in clear language, though they may occasionally drop phrases likeentry path overlaporinscribed circle diameter. Townspeople raise concerns. Roundabouts are not safe, they say. They are confusing. They are bad for pedestrians. They will hurt local businesses. They are more expensive than traditional solutions. The local newspaper reports this, adding some man-in-the-street comments from "area drivers," who profess not to like roundabouts, even making dark references to "circles of death." Then, the roundabout is built, the safety record improves, traffic congestion doesn't seem any worse than before, and the complaints begin to fade faster than white thermoplastic lane markings in the heat of summer.