Announced this morning at LA Bike Week’s kickoff event in front of
LAPD headquarters, Metro will be lifting restrictions on when and where
you can bring your bike onto Metro Rail (the Purple, Red, Blue, Green,
and Gold Lines).  Current policies give Metro staff the discretion to
block riders from transporting bikes on the rail network during peak
hours (6:30-8:30 a.m. and 4:30-6:30 p.m.), if a given train is too
crowded to accommodate them.

However, this morning’s MTA press release notes that, as of this
summer, Metro Rail riders will be free to bring their bikes aboard at
any time in specially designated parts of light rail and heavy rail
trains, pending the installation of new signage designed to guide
bicyclists to the preferred train sections.

According to Metro Senior Communications Officer Jose Ubaldo, the
middle "articulated sections" of light rail trains (Green, Blue, Gold)
will be set aside for bicycles, because there is more available
standing room.  (Editorial aside: Though, I wonder how difficult it
would be to move a bike to a middle section of a crowded train at rush
hour, but this seems like a good place to start.)

For travel on the Red and Purple Lines, bicyclists will be
directed to the rearmost car of each train.  Ubaldo elaborated that
the Metro has already begun removing seats in the rear cars of subway
trains to make more room for bicycles.  The process should be
finished within the next six weeks.

In light of the much-discussed frustration with the lack of adequate bike parking at MTA facilities (stations, "TODs"),
this policy change appears to be a step in the right direction. 
Assuming this decision spurs more people to come to Metro stations on
bikes, the MTA may very well have to contend with the added volume by
improving its existing bike parking facilities in number and quality
(though of course nothing is guaranteed).