Not specifically related to the exact topic, but I remember this hill where I grew up. There were some bus routes that crossed the main road going up this hill, including one that actually went through narrow undivided roads. Big buses like GM New Look or Gillig Phantoms.
But it was really weird because I’d often see buses from different agencies going up and down that hill. It was obviously for some sort of training, as the road itself didn’t have heavy traffic and it was a very steep hill.