Lelystad Vahl asked Jan Giskes (traffic engineer) to join the new team for the Lelystad municipality. Together, in addition to the grid plans, they realized many car speed reduction solutions. In their view, it was also necessary to modify the main design of the divided traffic system. Culemborg Jan Giskes, head of the Traffic Department of the municipality of Lelystad (1978-1984), became director of the Public Works Department in Culemborg in 1984. He brought Joost Vahl to Culemborg in 1985. From 1987 to 2000, Vahl was architect/urban planner there. A new development plan for the Goilberdingen neighborhood with neighborhoods along a ring road was transformed into a grid plan with streets, avenues, canals and quays. The plan with a network of paths was incorporated into the polder. This allowed as much affordable housing as possible to be built while eliminating operating deficits. With the help of a City Management Plan, a Culemborg Traffic Plan (VPC) and an alternative green policy, multidisciplinary work was done, over a number of years. The entire city was to be redesigned, with the goal of creating a green utility city; with priority for slow traffic everywhere.