The bridge you're crossing passes over the former route of the Sperillbanen, a railway that once connected Hen Station to Lake Sperillen. The 24-kilometre line opened in 1926, built primarily to transport timber from the forests of Ringerike. The Begna river below wasn't suitable for log floating, so the railway provided an alternative.
The line was constructed as a job creation scheme during difficult economic times in the early 1920s. A ferry connection at Finsand carried goods onwards across Lake Sperillen.
Passenger services were added but proved unpopular, ending in 1933 after just seven years. Freight continued until 1957, when the line closed permanently.
Today the tracks are gone, though some industrial sidings remain in use. The railway's short life reflects a common pattern in Norway: lines built for specific industries that couldn't compete once road transport improved.