I was wondering if these were viable in San Francisco, but it looks like they bore tunnels 20 ft in diameter [0] to fit their inefficiently large Muni Metro car

I was wondering if these were viable in San Francisco, but it looks like they bore tunnels 20 ft in diameter [0] to fit their inefficiently large Muni Metro cars. Another example of SF overspending on things they didn't properly think through. 0: http://archives.sfmta.com/cms/apress/documents/CentralSubwayTunnelFactSheet2012.pdf http://archives.sfmta.com/cms/apress/documents/CentralSubway...