During the trials in Zwolle and Giethoorn, we conducted 18 months’ worth of visual inspections to establish whether vermin started nesting in the installed bike paths. The underground cavities were inspected with the aid of cameras. Based on these visual inspections, we concluded that the elements were not occupied by vermin at any time. The geotextile ensures that the elements’ cavities remain free of soil, roots – and, as it turns out, vermin.