I visited this site in August 2012. I took a train from Nordagutsu through Hjuksebö to Notodden to visit the largest stave church in the world on my way back to Oslo on the same day.
The railway between Hjuksebö and Notodden is supposed to be part of the World Heritage Site and is apparently still in use. I happened to take this photo of the train on the railway because I thought it was cute.