CA Veh Code Section 21953

Whenever any pedestrian crosses a roadway other than by means of a pedestrian tunnel or overhead pedestrian crossing, if a pedestrian tunnel or overhead crossing serves the place where the pedestrian is crossing the roadway, such pedestrian shall yield the right-of-way to all vehicles on the highway so near as to constitute an immediate hazard.

This section shall not be construed to mean that a marked crosswalk, with or without a signal device, cannot be installed where a pedestrian tunnel or overhead crossing exists.