That's fair. And also, the environment is probably different, as in more dust in the tunnels, etc. But to stick with French technology, the Paris metro, for al

That's fair. And also, the environment is probably different, as in more dust in the tunnels, etc. But to stick with French technology, the Paris metro, for all its issues, does have working speed gauges. Some lines still use rolling stock from the 60s and 70s.