Like Boston, New York, Chicago, and many European cities, Philadelphia had a plan to build a comprehensive subway system early in the 20th century. Hidden City Philadelphia describes why most of it was never built.

The “Taylor Plan” outlined creating subway lines along Chestnut, Walnut and Arch Streets, a loop to distribute riders of the Broad Street Subway around City Center, a spur into Northeast Philadelphia on Roosevelt Boulevard, and a line along the Benjamin Franklin Parkway to points north. In his plan, Taylor outlined this Parkway line as an extension of the Broad Street Line, which eventually opened with service from City Hall to Olney Avenue on September 1, 1928. The Parkway-Roxborough (or Northwestern) line would have started as an subway at City Hall and then proceed below the Parkway to 29th Street, where it would have continued as an elevated line to Henry Avenue, following that road north past Wissahickon Creek…

The majority of Taylor’s planned routes never came to be nor did Philadelphia’s original transit master plan. Taylor was replaced in 1916 by a more pragmatic transit commissioner, William S. Twining, who took exception to many of Taylor’s ideas. Where Taylor saw transit as a stimulant of growth, Twinning believed that lines should only be built where there was already demand…

The last gasp of an enhanced mass transit system came in July of 1929 when Mayor Harry Mackey signed an ordinance for a ten-year transit program that included the Ridge Avenue subway line, the Locust Street subway line, and several other never-built transit routes. The Mayor authorized a $55,000,000 loan that never materialized. Unlike New York City, Philadelphia did not move forward with subway expansion projects to alleviate the city’s crushing unemployment rate during the Great Depression.

It’s a sad missed opportunity. It could still be done, and in fact it is being done throughout the developing world today. But U.S. leaders generally do not have the vision or imagination to consider even the possibility of picking up a plan like this.