It references other patents (prior and subsequent).
How would liability play out for the construction company in a Japanese court? It's already a low margin competitive industry so passing risk management costs onto customers (the cost of the people monitoring the holes) is likely more practical than risking all profits evaporating and years of litigation, especially if insurance has anything to say about it.
In Australia we certainly don't have those people, construction companies just use a few signs, some cones and barricades and that's all that is required to be compliant. If someone falls in the hole they shouldn't have walked past the cones!
Not the case in Victoria. Pretty normal to see a couple of workers standing near the site entrance making sure pedestrians don't get run over by a truck. Or standing in front of a closed footpath, directing pedestrians to cross the road.
There's pretty strict rules around keeping the public out of construction sites and excavations. Putting a couple of cones around a hole is definitely not all that's required.
There's absolutely a limit where adding another person only adds marginal safety. For instance, children who don't know they should not jump to jump a barrier and then go into a pothole should not be allowed alone on the streets. We are not talking about a random hole in the street, these things are already heavily warded in Japan with barriers and signs AND on top of it there's also workers AND on top of it the mentioned security guards. My argument is, many or all of these security guards are not needed.
Here is the thing: there are adults who know all this and they fell into a potholes by accident, or momentary negligence
The privitization is split into different companies, the best having had a 30 year contract to revitilise their line, and they've done wonders with it, while one of the worst was (pre covid) run to the exact orders of the government
You mean vs allowing those people to spend their time on something that might instead be more productive for society?
If that person is going to spend an hour doing something, is that truly the greatest contribution they can make? Maybe it is! Then again, maybe not.
There's lots of examples of that, people doing things that you would see brutally optimized out of western city and those cities I feel are worse off for that optimization.
One way to look at it is that with their wealth they've decided to employ more people and do more good, versus pocketing the profit and calling it efficiency.
The famous railway networks in Japan are actually privatized rail companies which was very surprising to me. When the rail companies privatized in my country they immediately became worse, as they were suddenly serving a very different purpose. Staff were let go, the trains are cleaned less often, services were cut. That kind of thing.