Arterials are types of roads designed to carry high volumes of motorized traffic. They are an integral part of transportation systems worldwide and exposure to them is ubiquitous, especially in urban areas. Arterials provide access to diverse commercial and cultural resources, which can positively influence community health by supporting social cohesion as well as economic and cultural opportunities. They can negatively influence health via safety issues, noise, air pollution, and lack of economic development. The aims of public health and transportation partially overlap; efforts to improve arterials can meet goals of both professions. Two trends in arterial design show promise. First, transportation professionals increasingly define the performance of arterials via metrics accounting for pedestrians, cyclists, transit riders, and nearby residents in addition to motor vehicle users. Second, applying traffic engineering and design can generate safety, air quality, and livability benefits, but we need evidence to support these interventions. We describe the importance of arterials (including exposures, health behaviors, effects on equity, and resulting health outcomes) and make the case for public health collaborations with the transportation sector.