Yes, as I was busted by a track maintenance fellow while searching for my lost cat. He told me he could fine me, even though he didn't. The track was in a heavily touristed area (right next to Red's) and though there is a constructed opening in the chain link fence, people are not allowed to walk on the tracks.

Took 6 weeks but we found the cat and she was living there, by the tracks.

I grew up in CA and we always walked on the tracks, crossed over the tracks etc. No one ever said anything. But I guess it was technically illegal and 20 years later a pedestrian bridge was constructed and cost several million dollars (and had to be ADA compliant though how a wheelchair could get to that bridge was beyond me). Maybe they paid for it out of the fines?