The first highway was a bit crowded, but soon I turned off onto this tiny road and all traffic practically disappeared. The route involved going up to the 1400-odd meter elevation, then down to join up briefly with the busy main highway (a maelstrom of trucks and tunnels, but only for a few kilometers), and then onto route 84 for the main Norikura ascent up to the 1600m level. Taking things leisurely, and stopping once at a very nice minshuku to ask them to refill my water bottle, I made it just before dark.
This mountain lodge is actually the youth hostel... and a bona fide onsen. Having arrived around dark, I didn't realize the setting was so lovely. It was great in other ways as well; the stores up here actually had a couple of Japanese microbrew beers, one of which (YonaYona Ale from the Karuizawa area) would be an award-winner in any country.