Deer and Road Traffic Accidents: Options for Management

Statistics from the U.S. or from Continental Europe suggest that damage to persons and property arising from road or railway accidents involving deer amounts to a very significant annual total and is increasing everywhere. Despite this, the relative efficacy or cost-effectiveness of different control options is poorly understood. This review presents an analysis of deer movement patterns in relation to roads in order to try and develop some general conclusions about the probable or expected pattern and behaviour of road crossings. Based on such framework the various possible options available for reducing accident rates are more formally evaluated. The review focuses primarily on deer and roadside management within Europe. Approaches to the management of deer on roads consist either of methods to increase driver awareness of deer (deer warning signs) and/or methods to reduce deer crossing activity or change the pattern of crossings (fences, reflectors or chemical repellents). Effective reduction of deer road-crossings can only be assured in erection of a genuinely impermeable barrier fence. Cost considerations usually result in erection of barriers which are only partially effective. Such fencing must be viewed merely as a deterrent to crossing and not an absolute barrier; effectiveness can be enhanced by providing alternative means of passage, thus reducing the probability of deer intent on crossing, forcing the fence. Some means of exit (one-way gates, deer-leaps) should be provided for animals that do get on to the carriageway and are then unable to escape. Provision of fencing, with the additional structures of one-way gates and underpasses, is likely to be extremely costly; such high costs may only be justified in regard to major roads. For minor roads where traffic flow is lighter and intermittent, deer-mirrors or game-reflectors are a more economical and a more appropriate solution, since the intention is to delay crossing, rather than prevent it. The effectiveness of both fencing and mirrors may be reinforced in especially sensitive areas by erection of appropriate road signs to increase driver awareness.