I still don't get it, the only part of the train tracks I can walk on is the one that leads downtown (so of course it's north of the beach). I don't have any other part of my train tracks I can walk on, but nothing on it turns red.
The bridge that goes over the water.
The net glitch lets you clip onto the parts of the train tracks you can't normally stand on so you clip onto the OOB tracks and walk to the bridge.