This capability would no longer exist if this section was eliminated. The district of Rottweil explored the possibility between June and October 2008 of expanding Ringzug operations from Rottweil to Horb on the Gäubahn. As a result of an expansion, the Regional-Express halts in Sulz am Neckar and Oberndorf am Neckar would be eliminated. These plans failed when the towns of Sulz and Oberndorf expressed their opposition. In addition, as a result of the reactivation of the Rankbach Railway for the Stuttgart S-Bahn, the districts of Calw and Böblingen underwrote a study in July 2008 to explore the expansion of the S 1 line to Eutingen and Nagold.