In the 1960s there were plans to upgrade the rail network around Hanover. This led at first only to the establishment between 1965 and 1970 of regional commuter services on the east–west axis between Nienburg / Minden, Wunstorf, Hannover Hauptbahnhof (central station), Lehrte and Celle and on the Deister Railway. A further extension was omitted because of disagreement between federal, state and city region governments. In 1984, in preparation for the upgrading of the line between Wunstorf and Hannover, Seelze station was relocated and rebuilt with overtaking tracks. After Hanover won the right to build Expo 2000 in 1990, it was decided to bring forward the planned introduction of an S-Bahn network that was originally intended to be opened at a later date. On 12 November 1990 a development agreement was signed between the state of Lower Saxony, the Municipal Association of Greater Hannover and Deutsche Bundesbahn. In a relatively short time lines which for decades had remained virtually unchanged were upgraded considerably in and around Hanover.