A TRAFFIC DATA SYSTEM FOR YOSEMITE NATIONAL PARK

Yosemite National Park experienced a substantial increase in visitation during the 1980's and early 1990's, causing overflow parking, traffic congestion on the park's scenic roadways, and increased vehicular emissions. The park's General Management Plan and the companion Yosemite Valley Plan focus on improving the visitor experience and protecting and enhancing the park's resources, in part through redevelopment of the transportation infrastructure. A key component of the park's plans for transportation improvements is to gain a good understanding of how vehicles move through the park throughout the year. Building on that understanding, a real-time traffic information system has been proposed to aid in transportation planning, traffic management, visitor information, and emergency traffic management. The focus of this paper is the review of and identification of gaps in the park's existing traffic data systems, analysis of existing traffic patterns and demand in the park, and recommendations for future ITS development. The existing system review identified problem areas based on stakeholder interviews and knowledge of the park's safety, mobility, transit and general transportation goals. Current traffic patterns and demand were then categorized by trip purpose including overnight visitors, day visitors, park employees, and transit services, resulting in trip tables representing visitor and other travel during various seasons and days of the week. Special attention was focused on Yosemite Valley since it serves as the transportation hub of the park and receives more visitors than any of the park's other natural features and attractions. Using the gap analysis and trip tables, recommendations on systems requirements were developed for later use in the design of a detailed traffic data collection/ information system.