The caltrain tracks ran under the 280 freeway. Notice how the vertical supports were covered in steel to prevent them from crumbling in an earthquake. Also notice how the base of some vertical supports were covered in graffiti.

The grade crossing was also under the freeway where 16th street crossed the tracks. Notice how electric gates could be lowered to block cars when the train approached. Also notice the electric flashing lights that would warn approaching cars that the gates were about to close.

Notice that two gates lowered on each side of the tracks. Thus blocking cars from attempting to drive around the gates. Also note that the traffic signals were also tied to the rail controls and turns red when a train approached.

Off to the left side of this photo, notice the smaller gate that would lower to prevent pedestrians from crossing when a train approached.