Trail Planning

Abstract

The design of a walking or hiking trail is based on fine scale topographic conditions and varied criteria specific to the particular context such as aesthetics, views, con-struction cost, and environmental sensitivity. As a result trail planning is typically a product of expert knowledge, field surveys, and creative design decisions— often made on site. However, when high resolution data is available geospatial modeling can be used to identify routes optimized for travel time and suitability. To design trails with Tangible Landscape we can hand place waypoints on a physical model and then the optimal network connecting the waypoints is computed in near real-time. This approach—hand placing tangible waypoints and computationally networking the waypoints—combines creative, collaborative decision making with mathematical optimization. In this chapter we explain the theory and methodology for designing trails with Tangible Landscape and then discuss a case study, the design of hiking trail scenarios for Lake Raleigh Woods, North Carolina. 7.1 Trail Design Methodology Our approach for designing trail networks with Tangible Landscape combines the creative identification and siting of key waypoints like trailheads and scenic spots with computationally optimized routing between these points. With Tangible Land-scape we can place tangible markers by hand to automatically digitize waypoints. This allows us to work intuitively, feel the slopes and curvature with our hands, and easily collaborate. To find the optimal routes we compute the least cost path between pairs of waypoints over the terrain and a cost surface as a function of walking energetics. First we create a cost surface that represents friction—the additional time required to cross a cell. Next we designate waypoints, points through which we want the trail to pass. For each unique pair of waypoints we use the r.walk module to © The Author(s) 2015 A. Petrasova et al., Tangible Modeling with Open Source GIS,