Prefabricated fauna tunnel saves time

Traffic experiences little inconvenience during construction of fauna tunnel

To allow small game to pass the Europaweg safely, the Municipality of Assen chose to build an ecopassage between the Asserbos, the Twijfelveld and the Natura 2000 area Witterveld. In a very short time, the fauna tunnel was realized, causing hardly any inconvenience to traffic.

Safety for humans and animals

To connect habitats of animal species and ensure ecological coherence, a fauna tunnel has been constructed under the Europaweg in Assen. Thanks to this fauna tunnel small game - amphibians, reptiles such as ring snakes, mice, rabbits and foxes - can cross undisturbed and safe, and there are fewer collisions with animals, making it safer for traffic. This fauna tunnel is part of a larger system of connections.

Collaboration of ecologist and construction

The municipality of Assen approached Arcadis to design and install a fauna tunnel, in the southern ring road of Assen. The contractor branch of design and consultancy organization Arcadis acted as the main contractor in the realization of this ecocorridor. Because the Europaweg has a wide road profile and a wide median strip, we first checked with Arcadis' ecologist whether the monolithic fauna tunnel of ACO would have enough effect. After all, there are animals that need light here and there in the tunnel. Since the dense section is no longer than 10 meters, Arcadis' ecologist found that a monolithic fauna tunnel would be a nice solution.

ACO deliberately chose to develop monolithic fauna tunnels made of polymer concrete. The reason for this is that polymer concrete has a high flexural and tensile strength, eliminating the need for reinforcements in the concrete. This is because the amphibians and reptiles that move in it orient themselves to the earth's magnetic field, which makes it better to avoid reinforcements and thus metal-like products in fauna tunnels. This makes polymer concrete the best available product for fauna tunnels. Moreover, polymer concrete is a non-absorbent product, so frogs and toads can pass through the ecocorridor without drying out.

Minimal detour and no inconvenience to traffic

The Municipality of Assen wanted to cause as little inconvenience to traffic and bicycling school children as possible. Therefore, it was necessary to realize this fauna tunnel during the vacations. To ensure that the road section would be closed for the shortest possible time, ACO assembled the standard tunnel elements into a ready-made prefab fauna tunnel with a length of 4 meters.

The fact that ACO delivered the fauna tunnel prefabricated to the job site saved a huge amount of time. Thanks to a tight schedule, Arcadis was able to dig a trench in the road section the day before delivery. Because the precast concrete foundation was well cured, Arcadis was able to process the fauna tunnel immediately the next day and asphalt the following day. All in all, installing the ACO Pro Fauna Tunnel took only three days per roadway. Because ACO was able to deliver two precast elements per lane, only half a road section was closed at a time. As a result, minimal detour was required and traffic experienced very little inconvenience. Because the project was delivered on time, school children were also not inconvenienced.