>but JR shinkansen and other operators use standard.
That's irrelevant. The shinkansen tracks cannot be used for cargo trains: they're exclusively for high-speed passenger trains.
You can't share tracks between slow cargo trains and high-speed passenger trains. Not only is the scheduling impossible, but the cargo trains would ruin the tracks. The shinkansen tracks require frequent and thorough maintenance to keep them at the level needed for reliable high-speed service.
If you want to see what happens when you try to share tracks between cargo and passengers, just take a look at Amtrak. It's a complete disaster.
That's irrelevant. The shinkansen tracks cannot be used for cargo trains: they're exclusively for high-speed passenger trains.
You can't share tracks between slow cargo trains and high-speed passenger trains. Not only is the scheduling impossible, but the cargo trains would ruin the tracks. The shinkansen tracks require frequent and thorough maintenance to keep them at the level needed for reliable high-speed service.
If you want to see what happens when you try to share tracks between cargo and passengers, just take a look at Amtrak. It's a complete disaster.