The increase in ridership has been so rapid that on certain peak services passengers have been left standing at stations.
Under an agreement between Arriva Netherlands, the Province of Groningen (acting as regional transport authority) and Stadler Rail, the trains will be sent to Stadler's Bussnang plant in Switzerland between September 2014 and January 2015 for modification.
The regional lines in the provinces of Groningen and Friesland were among the first to be decentralised in the early 1990s, and were even threatened with closure at that time. However following decentralisation the number of passengers increased considerably and has forced the operator to repeatedly increase train frequencies, as far as the limited capacity of the largely single-track infrastructure allowed.
Studies are underway to assess the feasibility of increasing fast services between Leeuwarden and Groningen to three trains per hour at peak times, in addition to two regional trains per hour.
The changes could be implemented in 2017 following the completion of infrastructure improvements on the route. In the early 1990s, before decentralisation of regional train services, this line was served by just one all-stations stopping service per hour.
