Anpassning av vägmiljö och vegetation som åtgärd mot viltolyckor. [Modification of the road environment as a measure against traffic fatalities involving wildlife.]

Wildlife accidents are a global problem that causes human fatalities as well as physical and economical damage. Current preventive measures do not seem sufficient enough to achieve a reduction in wildlife accidents. The most accepted and effective measures are fencing and control of game populations. VTI report 753 presents an overview of the current knowledge about how the road area, and to some extent also the adjacent areas, can be made less attractive to wildlife through road environment and vegetation changes. The report deals with relationships between wildlife presence/wildlife accidents and the surrounding environment as well as road operation and maintenance. The relationship between wildlife collisions and characteristics such as road traffic, wildlife-population density, nearby land use and landscape characteristics are complex. It is therefore difficult to identify general wildlife accident measures that are effective for all kinds of wildlife and all kinds of situations. The road environment may be modified to reduce the attractiveness of resources in the road area. Modifications may be directed towards the maintenance (e.g. adjustment of mowing practices) or the structure or composition of the vegetation. Cutting and clearing of roadside woody vegetation are ways to improve the visibility for motorists but may also affect the attractiveness of the roadside vegetation to wildlife. For example, clearing of trees and shrubs in the winter may be very dangerous since it will attract moose to the road area, unless the branches are transported away immediately. Cutting of roadside vegetation probably favours the occurrence of attractive vegetation in the autumn and winter when performed early in the vegetation period. The risk of wildlife collisions is also influenced by adjacent land use. In areas with a high risk of wildlife accidents, attractive vegetation should be fenced or completely avoided in a buffer zone outside the road (20—100 m). This applies to, e.g., some agricultural crops and energy crops. The report also contains an overview of the choice of vegetation in the road environment in order to reduce the attractiveness of the vegetation at the roadside. The report presents a list of plant species and groups of species reported to be resistant to grazing by deer and/or white-tailed deer. (Author/publisher) This report may be accessed by Internet users at http://www.vti.se/en/publications/modification-of-the-road-environment-…