Planning for the upgrade between Cologne and Aachen started in 1988. In November 1989, the transport ministers of the countries involved in the PBKA project agreed on a schedule according to which the line would be completed in 1995. The project was also included in the Federal Transport Infrastructure Plan of 1992. In 1992, it was planned to complete work by 1997. Of the estimated cost of DM 1.1 billion, around DM 800 million was to be allocated to the section between Cologne and Düren, half of which would be provided by the federal government and half would be funded under the municipal transport finance law ("Gemeindeverkehrsfinanzierungsgesetz"). Around DM 150 million (as of 1990) would be allocated to the section west of Düren.