I think this have to do with legislation about preventive archaeology (what we are allowed to do, how long are we allowed to do it and who pays for this ?).
I can answer this for France. And probably for Japan with a few researches.

Another important part would be the differences between preventive archaeology and planned excavations. I think this part would be pretty the same all over the world, but who knows ?

So, if anybody has knowledge of how it works elsewhere, feel free to write an article !