I've driven under and over that bridge many times over the decades. Bernal goes over both Monterey and the railroad. Both Monterey and the railroad are at the same grade and are unfortunately too easy to cross by foot. You can also use Mapillary or StreetView to confirm that the Bernal Road bridge crosses all of it. The 2 bridges to the north and the next bridge to the south use the same layering scheme. Monterey, the sidewalk and railroad are at the same level and should be considered layer 0.

People have been known to cross this railroad and highway instead of the bridge at this area. In fact, Xander's Crossing to the north of here is named after a young child (Alexander Arriaga) that was killed by a train that was crossing the railroad in 2005 exactly where that bridge is located now. It was a tragic accident and all over the news. That area is pretty similar to this area.

There are not 3 layers here, and I'm sure of it.