If you're in LA, you can attend the big bash at the Staples Center today for the MTA rail system. Now carrying 327,000 people a day, the system carries as many people as the Bay Area's regional BART rail, although total Bay Area light rail/heavy rail ridership is right at 500,000 when you factor in Muni.
The LA Times story noting the anniversary breaks down into a debate over whether the initial blue line should have been a bus instead. I often think bus service is underrated, because it serves the very important role of getting low wage workers, many of whom don't own cars, to work. But in this case, the rail line hooked up with others that go into some fairly wealthy areas in the Valley as well as with future lines that will run between downtown and Santa Monica. Additionally, with close to 8,000 people per square mile, LA not only had the people to support rail, it had the population density, something we don't see with toy trains that get proposed in smaller cities.