The group picks streets for their architectural and historical significance, and includes Fifth Avenue in New York City and Duval Street in Key West, Fla. on this year's list.
The group said Grant Street was chosen "for the historic 19th century buildings and soaring 20th century skyscrapers ..."
The oldest surviving buildings are the Allegheny County Courthouse -- a castle-like stone structure -- and the First Lutheran Church, both completed in 1888. The street is also home to the city's tallest building, the 62-story U.S. Steel Tower, which opened in 1971.
The City-County Building and U.S. Courthouse and Post Office are other prominent structures on the brick street, which features granite curbs.