The contract for the concession to run the two S-Bahn lines from December 2019 to December 2031 was awarded in 2016 to Keolis subsidiary Eurobahn. However, VRR announced in September 2019 that it was terminating the contract with Keolis.

Information supplied by Keolis to VRR during the mobilisation phase showed that Keolis had only around half the required number of train drivers to operate the two lines, meaning Keolis would be unable to maintain the full timetable.

VRR and its partner authority Westphalia-Lippe Local Transport (NWL) awarded DB Regio an interim two-year contract until December 2021 whilst arranging a new long-term concession, which DB Regio has now won.

A fleet of former DB-owned class 422 EMUs bought by VRR is assigned to the two routes. Line S1 runs from Dortmund via Essen to Solingen and S4 links Dortmund, Lütgendortmund and Unna. The concession covers 4.8 million train-km annually.