Integrated Transportation and User Capacity Research in Yosemite National Park: The Numbers Game

The broad purpose of user capacity management in national parks is to identify the types and amounts of use that can be accommodated in a park, while desired resource and experiential conditions are maintained. Traffic management and transportation planning in national parks are increasingly recognized as inextricably linked with user capacity management. The purpose of this study was to develop a tool to integrate transportation and user capacity management in Yosemite National Park. The study consisted of three primary components. First, survey research was used to identify visitor-based standards of quality for crowding in Yosemite Valley. Second, regression modeling was used to estimate statistical relationships between inbound vehicle traffic at park entrance stations and visitor use levels at recreation sites in Yosemite Valley. Third, regression model estimates of visitor use at recreation sites in Yosemite Valley were simulated with computer models to estimate the extent of crowding that occurs in the valley as a result of different levels of inbound vehicle traffic at park entrance stations. Simulation results were compared with visitor-based standards to characterize the quality of visitor experiences in Yosemite Valley associated with different volumes of vehicle traffic entering the park. Thus, the results of this study provide an empirical basis for managing vehicle traffic entering the park in a manner that maintains the quality of visitors’ experiences in Yosemite Valley. Further, the approach developed in this study can be adapted to other National Park System units to support integrated transportation planning and user capacity management systemwide.