New motorways often sever old connections, especially for people walking and cycling. It’s always good when those old routes are quickly reconnected, especially when that is done with a beautiful piece of infrastructure. The wooden cycle bridge at Grubbenvorst over the A73 motorway is a very nice example of such a reconnection.
When the bridge was opened, now exactly 20 years ago and shortly after the motorway it crosses was opened, it was the country’s first wooden cycle bridge over a motorway. There is at least one other now, the wooden cycle bridge at Harderwijk, which I showed you earlier.
The cable stayed bridge was designed and built in 1995 by Rijkswaterstaat, the governmental body responsible for main roads (and waterways and flood control). The timber came from a company in Friesland, Groot Lemmer, experts in building high-tech wooden bridges.
Cable stayed bridges made from timber are suitable for larger spans up to 100 metres. In this case there are two pylons also made from timber. The entire bridge is kept as slender as possible. The type of wood that was chosen, azobe wood from Cameroon, is very homogenous. This means you can calculate the forces the bridge has to endure just like you could if it had been made of steel. Computer programs can help you get the optimum: a strong bridge using the least amount of material. The main span of the bridge is 45 metres, the total length is 154.1 metres. The construction height of the bridge is about 1 metre. The pylons lean outward and they stand almost 18 metres tall.
Groot Lemmer imported the azobe timber from Cameroon. At the time there were already laws in effect in that country to protect its woods. The timber was grown and harvested in a sustainable way. Azobe wood is strong and resistant, making it useful for demanding constructions outdoor. It doesn’t need a coat of paint or any other treatment, so there is almost no maintenance necessary. The expected life span of the bridge is 80 years. That means the video shows the bridge at a quarter of its expected life.
The bridge was subject to severe vandalism in its very early days. Some old pallets were set on fire against the bridge, but the wood proved that it is very resilient and that it doesn’t burn easily. There were only some black spots, but no real damage. The heat of the fire did crack the concrete of the anchors, but that could be fixed easily.
A plaque states the opening date, the 4th of February 1996, and the bridge’s name: “De kortste waeg” meaning “the shortest way” in the local Limburg dialect. But if you look at the map, you see that it is hardly ever the shortest way for anyone. The main road crossing the motorway (Californischeweg) has excellent cycling facilities and is almost always shorter, especially if you go to the hamlet of Californië in the direction of America or even Siberië. These odd names for villages in the south of the Netherlands were given in the late 19th century, when peat was harvested in this area. To emphasise how remote these new workman’s settlements were, they were given names that imply ‘far away’ for people in The Netherlands.
That this cycle route is not a main route is clear from the fact that it is not lit at night. The bridge is also a bit on the narrow side by today’s standards. The inclines are quite steep and they are also not smooth. The grade of the access ramps is not constant, but varies at bit. That gives you the rather unpleasant feeling of riding on waves, going up and down.
The bridge is part of the main recreational cycle network (the numbered junctions network) and when you cycle for recreation it is perfect to be away from motor traffic in the woods even when that means you take a small detour. This wooden cycle bridge has given people the opportunity to ride safely and in a pleasant way to the other side of the motorway for already 20 years now and it is still looking very good!
Cycle bridge in Grubbenvorst
Ride on the bridge