I found the official Ministry documents page in Japanese[0]. Looks like it's more like dedicated closed freeway system for fixed-programmed autonomous semi trucks, than actual 500km-long belt. Whether it's going to be rubber tired or metal wheeled is at least officially left TBD for now.
Funny detail: Asahi Beer is asking in a slightly roundabout way to make it able to handle heavy objects and beverage-specific pallets, with a picture of a metal beer tank for illustration. They haven't decided if it's ever built or where depots will be - but it must carry beer IF they're going to do it!
Funny detail: Asahi Beer is asking in a slightly roundabout way to make it able to handle heavy objects and beverage-specific pallets, with a picture of a metal beer tank for illustration. They haven't decided if it's ever built or where depots will be - but it must carry beer IF they're going to do it!
0: https://www.mlit.go.jp/road/ir/ir-council/buturyu_douro/inde...