Road construction, cycling infrastructure and green in perfect balance

Utrechtseweg, a road that runs between Zeist and Utrecht, was no longer able to cope with the projected growth in traffic, which is why it needed to be widened and a bicycle tunnel added so that cyclists could cross more safely. We were given various objectives for this road construction project. First of all, the physical and perceived safety and traffic flow for through traffic, especially cyclists, needed to be improved. In addition, the trees, plants and green spaces as well as the historical heritage value of the view (trees, historic mansions, etc.) along the road needed to be preserved as much as possible. And lastly, accessibility for local residents during redevelopment and in the new situation needed to be assured. For Mourik, this was a welcome invitation to come up with sustainable ideas and innovations that bring all interests into perfect balance.

Measurably safer, greener and more sustainable

Our first success came with the design of the bicycle tunnel, with better sight lines, no blind corners, construction of safer cycle lanes, and more light in the tunnel, all important aspects in improving physical and perceived safety for cyclists. We also positioned the new tunnel and the cycling infrastructure so that we could preserve more of the trees, plants and green spaces. Through smart phasing we completed 80% of the bicycle tunnel without road closures. We used 38% less concrete for construction by optimizing the reference design, and we used circular, modular prefab tunnel elements. This eliminated the need for formwork material, meant fewer transport movements, improved quality, and shortened the time needed to complete the works.  

In this part of Zeist there are beautiful old oak trees that frame the heritage mansions and estates. We rethought the redesign from “green along the road” to “a road in the midst of green”, as it were. Narrow sidewalks, more space for trees, plants and other green aspects, relocation of cycle paths, and the cycle tunnel to preserve the old oak trees. In total, we cut down 40% fewer trees than anticipated in the tender. We also devised various sustainable solutions. For example, rainwater is now directed to the soil rather than the sewer, a major improvement in water management. We also proposed ideas for dealing sustainably with rainwater, such as constructing bioswales (green channels to collect stormwater runoff), and an infiltration and drainage system in places where there was room to place such a water buffering feature. 

Smart phasing, less disruption

One of the original requirements in the contract was the simultaneous redevelopment of Utrechtseweg and the construction of the bicycle tunnel. Ultimately, we proposed a different phasing: first the road and then the tunnel. The main argument was reducing road closures. Instead of a prolonged period of detours and delays, we now had just three cleverly planned weekend closures – with completion still on schedule. And businesses and offices remained fully accessible throughout. Our colleagues from Traffic & More helped with the phasing, traffic control measures and contact with local residents and businesses, which consisted of the things we always do, like organizing online or physical information evenings, sending out letters to the local residents, and talking to those concerned in person. We also built a physical grandstand where local residents could sit and watch as the bicycle tunnel took shape. And we used the BouwApp for communication with local stakeholders.

This contract was based on a Team Value model, and that suited us perfectly: the approach gave us a lot of freedom to optimize and hold an open dialogue with the client in the form of meetings, talks and interviews. Team Value assumes equality of client and contractor and rests on the “power of together” in the pre-contractual phase. The municipality itself set a good example, with plenty of room for consultation and dialogue. After winning the contract, we followed this up with a monthly feedback session to discuss the collaboration, guided by an external coach. We found this experience a pleasant one. Open communication leads to greater mutual understanding, connection, and more scope for solutions and innovations.