The cows grazing here seem to be unaware of the motorway close by. It figures: they can hardly see it. Pike perches, stoats and the lone canoeist probably notice even less. And still, they definitely do cross a motorway, just as easily as the godwits overhead.
From farmhouse kitchen tables all the way to the Dutch parliament: the (im-)possibilities of a motorway between Delft and Schiedam have been debated for two generations. Finally, in 2010 the decision was made: the motorway will be built. The aim: less traffic congestion between Rotterdam and The Hague, and a better accessibility of Schiedam and Delft. Residents in the area agree with the plans, on one important condition: the least inconvenience possible, for the natural environment and for themselves.
To meet this condition, parts of the motorway in the open polder landscape have been constructed halfway underground. In the urban areas, the motorway fully disappears underground in a ‘land tunnel’. The landscape around it continues right up to the motorway’s edges. How to achieve this? With a comprehensive plan for the design and integration of the motorway in the landscape, with special attention to greenery and pollinators.
An aqueduct/ecoduct enables small animals, such as stouts, newts, toads, fish and birds, to cross the motorway safely and naturally. And it allows canoeists and walkers to cross the A4 as well. The aqueduct/ecoduct merges with the surroundings, fitting smoothly into the landscape. With its width of forty yards, it is an essential stepping stone for wildlife and people moving between Midden-Delfland and the Green Heart of the Randstad.
From the car, the landscape is invisible, because the A4 has been largely constructed below the surface of the surrounding landscape. From a bird’s viewpoint, however, a journey between Delft and Schiedam means traversing four distinct areas: the leisure zones on the edge of the city of Delft, the peat meadows of Midden-Delfland, the elevated parklands between Vlaardingen and Schiedam, and traffic node Kethelplein.
Starting point for our design is the uniqueness of each of these different spatial units. In other words, the basics are the straight ditches and grasslands of the peat meadows, the wild wooded tracks of the city’s edge, the urban parkland with beautiful trees of the tunnel roof and the striking design of an important traffic node.
The landscaping along the A4 helps to blend the motorway with the surrounding landscape. We chose farmer’s fences instead of barriers, and cart tracks instead of broader maintenance roads. This keeps the difference between ‘high tech’ motorway and ‘low tech’ historical landscape sharp and clear.
We also selected plantings native to the region. We included different genetic variations and made sure these were distributed well. The result: rich diversity and protection against excessive losses by disease or plagues. Thanks to the continuous flowering periods over the course of the year, the verges of the A4 provide bees and other pollinators with a rich source of nutrition in every season.
A paradise for bees and other pollinators, as a small counterweight to the massive insect loss of recent years. That is what the seven kilometres long ‘Honey Highway’ along the route is. A special flower-mix of 44 native species was sown, to create the ideal habitat for insects. This project was instigated by the Honey Highway foundation, a local initiative we continue to sponsor proudly and enthusiastically.
– landscape architect/ partner Stijn Koole, BoschSlabbers
Water along the sheet piling of the motorway makes railings unnecessary, and significantly lowers construction costs.
A clear distinction has been made between the “high-tech”, enclosed world of the motorway and the “low-tech” outside world of the surrounding landscape.
Near Schiedam, motorists seem to drive into a ‘fold’ in the grassland carpet. The roof of the land tunnel houses a (sports) park.
From the surrounding area, the highway is hardly noticeable. As a result, the openness of Midden-Delfland has been preserved.
Title: A4 Midden Delfland
Location: A4 Delft - Schiedam
Size: 7 km
Contractor: A4All (combination Boskalis, Heijmans, VolkerWessels)
Cooperation: Zwarts Jansma Architecten
Type: Tender, provisional and final design
Prize/publication: World Architecture News (WAN) Award 2016 (cat. Infrastructure)
Image credits: BoschSlabbers, Jeroen Musch, YourCaptain luchtfotografie, Jörgen Caris, HoneyHighway, ZJA
Project code: HL 10-29