Trails as accessibility management tools in mountain areas

In mountain areas a trail network is usually present and strictly interconnected to the forest road network, both allowing the access for transportation and recreation. Therefore trail network can be considered a ramification of forest road network, which integrates accessibility in forest area. If forest road can be travelled by different motorized vehicles, from trucks and trailer to small 4WD cars, trail network can be mainly walked or travelled by small ATV. From this point of view trails represent a basic infrastructure for rescue interventions during which a widespread presence of operators is required. In order to evaluate the role of a trail network in a mountain area a methodology has been set up to assist the decision on determining the access time of the rescue crews along the trail network from the main road network. The methodology is based on a detailed GPS survey of the trail network considering the barriers for the pedestrian and motor vehicle accessibility. The resulting trail network is thus used to support the evaluation of the time/cost-distance according to the pedestrian or motor vehicle accessibility. Furthermore to increase the accuracy of the methodology, the evaluation of the off-trail pedestrian accessibility is also investigated according to the terrain geomorphology and the forest type. The resulting GIS model is a tool based on the GIS cost surface raster analysis. The methodology has been applied in a forest area in the North-eastern of Italy and the experimental design has been analyzed in order to identify the most difficult area to be reached and to evaluate the most reliable access for rescue crews.