Last weekend I popped down to London for the meet up of various British board members and during the day used the London Underground several times. Now for some reason I've always just really liked the Tube and quite enjoy using it, having something of a soft spot for it. So the question is, is it possible for more cities other than London to develop similar rapid transport systems that could survive and flourish to modern times? I'm putting this in the Before 1900 forum as realistically they'd need to be done then for any chance of success due to the various factors affecting infrastructure projects in the UK, you haven't got a hope in modern times.