Welcome to the thread E_AL, (
my bizarro world acronym for engineeral).
train service other than the obvious P&E and LARy, did indeed run on surface roads competing with vehicular traffic in los angeles.
one of the most amazing instances of this was the train service utilizing the Southern Pacific's Central Station at 5th Street and Central Avenue.
The rail service utilizing this depot actually ran on Alameda with heavy automobile and truck traffic
this view is looking north between central and alameda from 6th street. the tracks on alameda running in and out of the depot are clearly visible
Source:
LAPL
Another view looking west across the central station train yard
Source:
LAPL