Huntington Avenue
By the 1930s, auto traffic through Copley Square and Boylston Street (which, unlike Huntington Avenue, lacked dedicated medians for trolleys) caused major delays to streetcars. Mechanics station (named for nearby Mechanics Hall) and Symphony station were opened on February 16, 1941, as the two new stations of the Huntington Avenue subway project. The project was constructed by the Works Progress Administration during the Great Depression and allowed streetcars from Huntington Avenue to go underground through Copley Square, cutting 15 minutes off trip times.