Since 1978, the Stuttgart–Weil der Stadt section has been integrated as line S 6 of the network of the Stuttgart S-Bahn. At first DMUs continued to Calw as feeders to the S-Bahn. As part of the establishment of the S-Bahn, a 1 kilometre-long flying junction was built in Zuffenhausen station for the line to Weil der Stadt with an elevated platform and ramps with a 3.0 percent grade.
