A broad, multi-lane avenue within an urban center, typically with a planted median and flanked by pedestrian promenades designed to encourage strolling and lingering. Much wider than typical streets, boulevards evolved as promenades built on top of the ruins of ramparts or other encircling fortifications as a city outgrew the space within these defenses.

Since Baron Haussmann’s redesign of Paris in the mid-nineteenth century, the characteristically curved boulevards straightened, becoming primary travel corridors cutting through smaller street grids. In the U.S. this legacy manifests clearly in New York City’s Park Avenue and Boston’s Commonwealth Avenue, as well as in the grand plans of the McMillan Commission and Daniel Burnham for Washington, D.C. and Chicago, respectively. Unlike parkways, which frequently have limited access, a boulevard is more often highly engaged with the city.