Roundabouts are for rich people: who gets traffic control devices and what to do about it

Almost every intersection has some form of traffic control. Stop signs and signals are ubiquitous, but recently roundabouts have become more common in the US. Roundabouts are generally safer than other intersection types, making their distribution an equity issue. We motivate this research with qualitative work conducted in a working-class neighborhood in Durham, North Carolina, where community advocacy for roundabouts to improve safety has been unanswered by transportation officials. We expand this to the whole of North Carolina, modeling which intersections receive traffic signals, roundabouts, and other intersection designs. We find that impoverished and minority neighborhoods are more likely to have signalized intersections—largely a traffic flow intervention, rather than a safety one—while they are less likely to have roundabouts. We identify several partial explanations for this—notably that older neighborhoods, where less advantaged groups often live, have fewer roundabouts overall. To address the issue, we propose an expanded process of Intersection Control Evaluation. This is a formalized process for evaluating the safety, traffic flow, community, and environmental impacts of traffic control devices. We propose that this be undertaken periodically for all intersections above a certain traffic volume, to ensure safety is adequately considered in all types of neighborhoods.