S4 (Rhine-Ruhr S-Bahn)

[2] Extension of the S 4 line from its current western end in the tunnel at Dortmund-Lütgendortmund was formerly planned to be implemented with a target of opening it in 2015.

The Emschertal-Bahn (RB 43) Regionalbahn service would only operate between Herne and Dorsten.

The Emschertal-Bahn runs between Dortmund-Bövinghausen and Herne every hour, but the S2 would run between Herne and Essen every twenty minute as an S-Bahn service, so the Verkehrsverbund Rhein-Ruhr would have to fund the increased services through savings in other areas.

Upon taking office, the transport minister Oliver Wittke called for all such proposals to be re-evaluated.

The line extension has been removed from the integrated transportation plan for North Rhine-Westphalia; a resubmission is possible from 2015.