A beautiful new bicycle tunnel was officially opened last Thursday in De Bilt by representatives of the Province of Utrecht and the municipality of De Bilt. The new tunnel is part of a bigger plan for five cycle tunnels in the municipalities of De Bilt and Zeist, east of Utrecht, around the main road to Amersfoort, the N237. The plan for these tunnels was developed by the Province in collaboration with the local municipalities in an effort to improve conditions for all types of traffic in the area.
The new cycle tunnel was officially opened by Arne Schaddelee, the representative of the Province of Utrecht, who has mobility in his portfolio and André Landwehr, the executive council member for traffic of the municipality of De Bilt. After removing a fence they gave passers by a set of bicycle lights which can be very welcome in this darker time of the year. The tunnel is part of a bigger plan for five bicycle underpasses in the area around the N237, the main provincial road from Utrecht to Amersfoort. Four tunnels were planned in the municipality of De Bilt and one in the municipality in Zeist. The goal of the Province with this five tunnel project was threefold:
- decreasing waiting times at intersections for all types of traffic
- decreasing the number of traffic casualties
- improving the comfort, directness, traffic safety and travel speeds on the main cycle network.
In 2010 the budget was set at 10 million euros or 2 million euros for each tunnel (which included all planning costs and building costs). The first tunnel was commissioned in 2014 and opened late 2015 under the Universiteitsweg (Road to the [Utrecht] University) in De Bilt.
The second tunnel was opened one year later, late 2016, near Zeist but still officially in De Bilt under the widened part of the N237 to Amersfoort. That road is aptly named “Road to Amersfoort” (Amersfoortseweg) at that location. At the time this road was crossed by 1,200 people on bicycles every working day. Although the budget for both tunnels was 2 million euros per tunnel, building the first two tunnels had cost 4.6 million euros in reality.
Tunnel number three posed a few challenges. During the planning phase it became clear that the number of people using it would be too low, which meant not all goals would be met. A location a bit more south would be much better, but at that location two options were viable. This delayed the process so much that the tunnel has still not been built. The most likely location for this tunnel is now the intersection of De Dreef and Kromme-Rijnlaan with Utrechtseweg. The municipality of Zeist will further develop the plans for a tunnel at this intersection. A revised budget of 2.1 million euros is now available for this last tunnel to be developed. (The exact amount left from the original 10 million euro budget, now that the first three tunnels have been built and the fifth was cancelled.)
During the research of tunnel number five, again in De Bilt, (at the intersection of Soestdijkseweg Zuid and Dorpsstraat / De Holle Bilt) it became clear that that tunnel could not be constructed there. The buildings in the old main street of the village (Dorpsstraat) are too close together to be able to build an access ramp there that would meet the latest design recommendations. Removing buildings for a cycle tunnel was not considered appropriate. It would be too costly and too disruptive for this part of the community. That is why in 2015 the plans for this tunnel were abandoned, instead the municipality improved the level crossing.
Tunnel number four was a bit special because there already was a tunnel at this location. This made it harder to convince authorities to spend money on a replacement tunnel. However, this tunnel under the Utrechtseweg (Road to Utrecht) in De Bilt was constructed at the same time as the road, in 1937, and it was never intended to be a cycle tunnel! It was originally a concrete box culvert, in other words a pipe to get water of a small river to the other side of the road. Only around 1955 the culvert was converted and did it become a makeshift tunnel for two way cycling and walking. Therefore the access ramps were too steep and the tunnel was much too narrow for the volumes of people using it. Already in the mid-1990s people and organisations like the local chapter of the Cyclists’ Union called for a replacement of this old inadequate little tunnel by something that would meet modern criteria. A lot of accidents and near misses were reported in the old tunnel. There were especially many pedestrian-cyclist-conflicts but also oncoming cyclists were often in each other’s way. The 2010 plan was a direct result of the calls for the replacement tunnel, but it would take until 2017 before the decision was finally taken to build it. The budget for this one tunnel had to be increased to 3.2 million euros.
Contrary to the decision making process, and much to the surprise of foreign visitors, building the tunnel took only a very short time. The preliminary measures such as removing trees and shrubs and moving pipes and cables started in July 2019. The tunnel itself consists of pre-fabricated concrete rings of 1.25 metres wide that could be placed in 20 minutes. The seams between these elements were sealed right away to create a watertight tunnel. The elements are kept together with tension cables running through all the combined elements. This process meant that the road the tunnel crosses only had to be closed for one weekend early September 2019. Because the tunnel under half the road was ready in that one weekend traffic in both directions could use that part while the rest of the tunnel was quickly finished. After finishing the raw built the tunnel was in use early November, but the official opening took place almost a week later, on Thursday 14 November, as described at the beginning of this post.
A striking feature of the tunnel is the work of art on the walls and ceiling. Bright red and blue lines cover the entire tunnel. Artist and graphic designer Hansje van Halem said she was inspired by isobars (contour lines) on the weather charts that are used by the nearby Royal Netherlands Meteorological Institute. This work of art was painted by 9 artists from De Strakke Hand, a collective that is locally well-known for striking murals in and around Utrecht.
Some finishing touches still need to be done. The old tunnel will become a wildlife tunnel. It will almost completely be filled with dirt so it is better suited for small animals which can use the tunnel to get safely to the other side of the road. A connecting small wildlife tunnel runs diagonally under the new cycleway leading to the tunnel. About 2,000 people cycled through the old tunnel every working day. Together with many pedestrians they are very happy with this new tunnel.
My video explaining the five-cycle-tunnels-project in the Province of Utrecht.
A ride through two (and a before-and-after of one of the two) bicycle tunnels in De Bilt.
BICYCLE DUTCH 
Occasionally I passed the old tunnel in a velomobile during rush hour! Nowadays there is also, at least fo my route, a more attractive crossing half a mile to the west.
Very practical approach to built these tunnels.
Very practical approach to built these tunnels.
Great story and vids, Mark, especially about the old culvert with its what would be state-of-the-art design if it was in Australia.
Thank you once again for your efforts.