West of the new residential development Leidschenveen, highway A4 is some 14 lanes wide. For pedestrians and cyclists this is a major obstacle. The urban plan provided for two overpasses but financial backing was uncertain.

Designing generated funding.

Next to serving muscle-propelled traffic, the northern viaduct is also capable of carrying a public transport line. The southern connection is mainly meant for bicycle riders and provides an alternative branch on the route between Zoetermeer and The Hague. Instead of worming underneath the flyovers of a gigantic spaghetti junction, this trail follows the inhabited world as much as possible.

Both viaducts are set on pillars as much as possible to avoid hefty dikes that would further impede movement of traffic at ground level. At the south-west side, were the prevailing winds come from, screens of perforated steel are installed to provide protection. Wind-force is reduced by half, yet the highway below remains visible and part of the travelling experience.