There are plenty of places where the pitifully bad systems that already exist are not just used, but used to well beyond their capacity.<p>Like... SF and environs, where the rail-based transit systems are basically all running hobbled all the time due to being way over capacity and way past expected lifetime of equipment. Caltrain just reported weekday ridership is now around 62,000, for example, but is struggling to replace 25-year-old equipment that breaks down on an almost weekly basis.