If they are being forced to allow access through private property, and injuries could occur on the private property, I do wonder why there hasn't been any cases? Are we sure it is private property and not some amount of reasonable public property allowed for access to the beach (which the owners might be pretending is private property and then being sued to allow access)? On a non-California beach I've been to, there are public access ways (about 20ft wide) between every 3 to 5 houses. The houses are free to block their own land, but they can't block the accessways, the beach, or the dunes because all of that is public property.
I would assume there have been cases, just not specifically about "tripping on a root". I can't actually substantiate that, though. The SEO of the "lawsuits about forcing public access to the beach" is really high, I can't find any lawsuits. I would assume there are some, even if the plaintiffs didn't win though? People in the US sue for everything.
> On a non-California beach I've been to, there are public access ways (about 20ft wide) between every 3 to 5 houses. The houses are free to block their own land, but they can't block the accessways, the beach, or the dunes because all of that is public property.
No, California went way farther than that. They mandated that the entire coastline up to the median high tide line (if I remember right), has public access in the 1974 California Coastal Act. In later court cases, the court ruled that if there is no feasible way to access that public area without crossing private property, private land owners must permit the public to cross their land to get to the coast.
It's a little messy for older developments, but for new coastal developments the state requires the developer to sign an easement granting the public rights to use the land. I think there are a couple of beaches that are still holdouts due to various old-timey contractual things, but in general, you can walk across private property to access a beach behind someone's house if there isn't a feasible public route (I.e. you aren't expected to rock climb down a cliff instead or hire a boat, but you should use the public walkway if there is one).