At the very least it's the law of large numbers.

For every careful citizen there is a tourist from somewhere where they have never seen trains run on the tracks. Add in herd/group mentality,the skate boarders in the ditch, people climbing down erosion control embankments, 60 year olds in sandals who remember doing this when 30, and the suicidal and somethings got to happen.

In a perfect world we would have handicap access to Blacks Beach and an underpass to the sand at Del Mar. Then the Nimby's could go back to complaining that all those strangers blocking their driveways and that there is too much traffic on Historic 101.