LA is slowly improving its transit situation from what it used to be, though unevenly. A light-rail line from downtown to Pasadena was opened in 2003, and the subway system is finally being extended, it seems, through some of the more densely populated area of the westside: http://en.wikipedia.org/wiki/Purple_Line_Extension
The Metrolink commuter-rail system also runs 500 miles of track, and is now a reasonable option if you commute during typical rush-hours. However, it has very little service outside traditional commute hours, and its overall ridership is not very impressive, especially given the size (it gets less daily ridership than the much smaller subway does).
The biggest issue with public transit in LA for commuting is the last mile problem. It's similar to the "last mile" problem of fast fiber optic cables to slow copper wires to homes. Here the issue is efficient and fast rail transit to extremely inefficient bus system for that last few miles from stations to work. I once tried to plan my commute using public transit and here's what I found:
1) Drive to rail station for park and ride? About 10 minutes, great.
2) Light rail to station nearest to my work place? About 30 minutes and covers 90% of the distance, awesome.
3) Station to my work place? About 1 hour using bus system...
I'll just drive instead since even with bad morning traffic I'll still get there faster because the bus system is really really bad.
I get a bit upset when I think about it because I can get there 90%, but that last bit is ruined by the stupid bus system.
In Europe they have these paths from a bygone era commonly known as sidewalks. In the US, we frequently have ditches which drivers treat as roadside garbage dumps.
Why don't you bridge the last mile with a bike? I have never been to L.A., but you should be able to just buy yourself a 7th hand old beater and park it somewhere next to the commuter station, then ride the rest of the way.
LA's MTA has a bike locker rental program, find out here [1]. It's worked for me; stash a beater bike at the "work end" of the train commute and ride the "last mile".
If the "work end" is in Burbank, here's the info on their bike locker rental program [2].
The Metrolink commuter-rail system also runs 500 miles of track, and is now a reasonable option if you commute during typical rush-hours. However, it has very little service outside traditional commute hours, and its overall ridership is not very impressive, especially given the size (it gets less daily ridership than the much smaller subway does).