A4 route design
In response to the rapid high-density construction along the Dutch motorways in particular, the many new exits causing major traffic congestion, and all sorts of unplanned developments encroaching on the scarce nature reserves, we were asked to provide a future vision for the A4 motorway.
This route design aims to improve the flow of traffic while restoring the interconnections between landscape, city and infrastructure in the area intersected by the motorway. We also want to fine-tune the quality of motorists’ experience of the motorway.
In our vision, new buildings are concentrated along local or provincial parallel routes, preventing ribbon development along the motorway. The slow traffic to industrial estates and residential neighbourhoods benefits as a result, and the motorway does not need any new exits and parallel structures. The sleek motorway that remains can easily be bridged by recreational routes and ecoducts. Landscapes and the fabric of the cities on either side of the motorway will see the benefits of this approach. In economic terms, it is an appealing option for such diverse sectors as distribution, professional services and tourism.
The choice of design for the A4 was defined by the metaphor of a river. The A4 meanders through the lowlands of South Holland like a river, sometimes splitting into main branch and secondary tributary, channelled to run through a city, frequently supplemented by forelands to reserve capacity for future ‘floods’, and often equipped with dikes to prevent noise from spilling over. Everyone enjoys the aesthetic qualities of rivers, so it serves as a useful comparison in the design process. With the river as a metaphor, design principles were developed that were aimed at improving the quality of the linear motorway landscape. At the same time, intersecting connections over and under this river are facilitated and strengthened. A river is also held at bay by the landscape it flows through: in densely populated cities, the river becomes more compact, with stone quays, bridges and tunnels, while more natural landscape gives it room to flow and broaden. This is exactly what we want for motorways.