IENE 2016

In 2013-2014, the Dutch National Roads Agency used a new approach to select a contractor for a road expansion based on ecological value. The tendering process actively challenged contractors to develop plans to minimise the impact on nature beyond the contract requirements, resulting in the selection of a contractor that had drawn up a plan that contained 55% of the maximum obtainable ecological value. This plan was presented at IENE 2014. In 2015-2016, the road expansion was constructed, allowing us to evaluate how much ecological value was eventually realised. The contractor created an extra 20 ha of heathland corridors to enable reptiles and other species to move between core habitats. The corridors included several infrastructure crossings. In addition, three new badger tunnels and two new pine marten bridges with accompanying fences were constructed. Reptile and mammal measures were created in collaboration with NGO’s and all nature conservation organisations owning land along the road involved in the project. A bat hibernation site that was unexpectedly discovered was successfully conserved without causing project delays, and was subsequently improved to host larger numbers of bats. Some measures could not be realised. For example, Ulex europaeus shrubs turned out to be too fragile for transplantation and one of the heathland corridors could not be constructed as a result of second thoughts of the land owner. Furthermore, the contractor did not deliver the anticipated quality when it came to the maintenance of temporary reptile fences. Considering the project as a whole, the natural environment of the road benefited from the road expansion project. Since the contract includes 16 years of maintenance, the contractor will continue to monitor all measures. Meanwhile, the National Roads Agency is repeating the new approach for another road expansion.