Interesting. I naively expected it to take the shortest/great circle route from Europe straight across northern Russia to Japan, but no, it actually loops the other way around the pole via Iceland and Canada.
Original route plan was exactly that, but there are reason why that route wasn't taken. This plan has been open for a decade aka ROTACS. But Russia started to build their own cable Polar Express - https://www.arctictoday.com/work-on-a-russian-trans-arctic-f...