While bouncing around the Internet, I found an official CALTRANS website examining the ped. friendliness of Union Station made in 2001. The engineers flunked the planning for pedestrian access (giving it a 3 out of 8) and gave lowest possible score for bicycle access.
For pedestrian acces, CALTRANS noted, "The Union Station is not connected with its surrounding uses by effective pedestrian links. Major hurdles are crossing N. Alameda Street from Chinatown, though Chinatown itself is pedestrian friendly. Due to Freeway 101 and rail track on the south and east of the site, access is further restricted."
For cyclists, "There are no existing bike routes around Union Station. Downtown Los Angeles has some designated routes but they do not extend across Freeway 101 to Union Station. There is no convenient bike parking location on site, except a few spots at the service entry behind the station which is very difficult to find."
Fast forward seven years, have things changed much?
For cyclists, things have gotten somewhat better. Wikipedia notes that "the few spots at the service entrance" reserved for bikes has grown to 24 bike rack spaces and 20 locker spaces. Designated bike routes now extend from as far south as Imperial Highway and as far east as La Cienega to the corner of Main and Temple, one block from the station.
However, for cyclists and pedestrians, the main barrier remains that the station is completely isolated from the east and North by I-101. What practical solutions exit for that problem aren't clear, it's pretty obvious LA won't be reconfiguring the freeway anytime soon.
There is one barrier that could still use some work. Crossings at Alameda remain confusing as the road is designed to move as many cars as possible at the expense of sensible pedestrian configurations. Six lanes of traffic separate the east and west sidewalks (where there is an east sidewalk) and pedestrian crossings aren't as abundant as a pedestrian destination would generally require.
Back in August, two New Yorkers blogged about their "Transit Oriented Honeymoon" and found the pedestrian accommodations around Union Station to be terrible. Their main complaint is that pedestrian crossings are prohibited at the intersection directly in front of Union Station.
One commenter noted that crossings are banned for pedestrian safety reasons, "...a crosswalk there would lead pedestrians to walk on the eastern side of L.A. Street. But a few feet further south, there is a huge on-ramp to the northbound 101 freeway. Cars turning from L.A. street to the 101 would be a danger to the pedestrians, so the city eliminated the sidewalk on the eastern side of L.A. street in this area. To discourage more pedestrians, they also prohibited the crossing where you were trying to cross."
In short, officials deserve some credit for fixing the bike storage problem and expanding the bike network in downtown LA. However, before Union Station is recognized for being pedestrian friendly, LA needs to come up with a better plan for Alameda.