The barrier effect of roads is now well documented and solutions such as fauna passages have been described (norm 640 690a, 640 691a 640 692, 640 694). Less well known is the mortality caused by specific engineering structures accompanying roads, such as transparent noise barriers or poorly adapted drainage systems. This research focuses on census all the remnant wildlife hazards, not already covered in the norm family "Fauna and traffic" and in defining solutions.
The objective of the project is to evaluate different problems of the wildlife with engineering structures of roads and railway systems and show possible solutions.
The work includes literature research, interviews with experts of the road / rail construction and the affected groups of animals, as well as a systematic collection of points of conflict and if present possible solutions in a selected study area.
The VSS has emitted a series of norms on fauna passages (SN 640 692- SN 640 699) with the goal of restoring as best possible connectivity. However fauna passages cannot solve all problems. A number of annexes structures cause high mortality and also have an impact on populations.
This research project has collected field knowledge on the impact of various structures on small animals and suggested mitigations measures. Wildlife specialists, herpetologists and maintenance people were interviewed. All significant structures for fauna were examined, pavement, borders, bridges, retaining walls, runoff systems, noise screens.
Depending on design these structures can have negative effects, acting as traps (collision against transparent noise screens) or positive effects, offering refuges for animals (stone walls, drainage pipes) or movement corridors for wildlife along transportation axes (natural verges). 140 measures, mostly with adaptations of engineering elements, permitting to reduce mortality and improve connectivity are described.
The VSS standards related to these structures are listed and their revision in order to integrate aspects concerning fauna suggested. The research report should serve as a reference for further standard revision and as a guide for engineers so as to diminish causes of indirect mortality and improve connectivity.
Upon completion of the research, a standard be drawn up, which serves as a working tool for decision-makers to minimise mortality resources modes of transport. The derived recommendations will ensure that the proposed solutions are technically feasible and financially viable.