New York City; Washington, D.C.; Boston; Chicago; San Francisco; and Seattle come out top, followed by a second tier of Portland, Pittsburgh, Denver, Philadelphia, Atlanta, Charlotte, and Minneapolis-St. Paul. Among 30 cities studied, San Diego, Dallas, Las Vegas, Tampa, San Antonio, Phoenix, and Orlando have the lowest walkable urbanism levels, defined by the percentage of office, retail, and multi-family development in Walk-UP places. The report was put together by Smart Growth America, an advocacy group, and academics at the George Washington University School of Business.