Off the Map: Natural Surface Trails in the Urban Transport Mix

Natural surface trails function as transportation infrastructure in cities across the United States, but they remain unmapped, unmaintained, and unprotected as transportation assets in most municipal planning frameworks. This research examines that gap through a case study of Chapel Hill and Carrboro, North Carolina, using GIS-based network analysis and practitioner interviews to demonstrate both what formal exclusion costs and what closing the gap requires. A school walkshed analysis comparing the formal paved network to the complete network including natural surface trails finds a 14% system-wide increase in residential buildings within walkable distance of the district's 26 schools, with individual schools showing gains exceeding 250%. Interviews with planners and advocates in Chapel Hill, Carrboro, and Asheville confirm the institutional barriers driving this exclusion and point toward practical pathways through them. The research concludes with five policy recommendations applicable to similarly positioned municipalities where natural surface trails are already serving mobility functions that planning practice has yet to recognize.