That's no longer the case. LA obviously has a whole lot of nightlife, and while buses that run 24 hours have been available, there's an extra comfort in knowing the subway is there for you too.
From the official Metro blog:
All Metro Rail lines will run until 2 a.m. on Friday and Saturday nights. That includes the Red/Purple Line subway, the Blue Line, Expo Line, Green Line and Gold Line.Metro Blog
•Trains will run every 20 minutes between midnight and 2 a.m.
•The Orange Line will run until 2:40 a.m. on Friday and Saturday nights in order to meet the last trains at the North Hollywood Red Line station. The Orange Line will also run every 20 minutes between midnight and 2:40 a.m.
•The plan at this moment is to begin late-night service on the weekend of July 27-28 but Metro is also working to determine if late night service is needed on the Silver Line, as well as working with Metrolink on the possibility of extending their service to connect with Metro’s.
The benefits of late night transit are extensive. It provides an extra level of comfort that you can get home and won't be stranded. Especially when you take into account the role the last train plays.
If service ends at midnight....you don't want to plan anything past 11:30pm, because of the fear that a slight delay leaves you stranded. By extending service until 2am, the comfort zone is now 1:30am. That's the difference between a USC student catching the 10:20pm screening at the LA Live movie theater or staying home.
Besides saving money on expensive cab fare, later service means safer trips home, as there's less of an incentive to drive drunk.
And it's not just drunk party people who benefit. Many low paying jobs have hours that don't quite match up with rush hours. If you're getting minimum wage, it's probably more likely your shift ends at midnight rather than 5:30pm. Now, at least on weekends, there's a comfortable train waiting to take you home.
20 minute headways and weekend-only service isn't perfect, but it's an excellent start, and it's better than what cities like SF and Boston provide. Indeed, even major subway-cities like Paris and London close their underground down at around midnight.
It's great to see LA take such great pro-rider move.