The initial €105.1m phase involves the upgrading and electrification of the 21km Tübingen – Herringen Ammertal Line and the 10km Ermstal Line from Metzingen to Bad Urach. Ultimately an eight-line core network is envisaged.

The decision to back the project means the state will be able to increase its financial contribution to the project if it fails to secure the necessary funding through German Rail (DB) or the federal government.

The state hopes to secure federal funding under the Federal Municipal Financing Act (GVFG). Under this programme, local infrastructure projects with a value of more than €50m are eligible for 60% federal funding if the state government can provide 20% of the cost. However, the GVFG currently only covers projects that can be financed and completed by 2019. Baden-Württemberg therefore plans to complete the first phase of the Neckar-Alb tram-train project by the end of the decade.