Abstract:This report describes the post-implementation evaluation plan for the Yosemite Area Traveler Information (YATI) system. The YATI system will offer users access to information concerning current road and traffic conditions, lodging and camping availability, and public transit and tourist activity information through changeable message signs, highway advisory radio, electronic information kiosks, travel advisory telephone system and access to a World Wide Web page. Each of these services will be evaluated based on the criteria of quality, demand, and cost. The evaluation plan measures these following goals of the YATI system: reduce traffic congestion, enhance mobility, and preserve/promote tourism in and around Yosemite National Park. The goal to improve air quality is not assessed in this evaluation plan. This report is a supplement and revision to the Evaluation Plan submitted to the Merced County Association of Governments (MCAG) and approved by the YATI Management Board in August 1994. In addition, the Plan has been substantially revised in response to comments received from the Management Board, Citizens and Technical Advisory Committees and MCAG. The evaluation plan also describes an institutional evaluation and a system performance evaluation. The former will identify how the working relationships and formal/informal structures between YATI participants have contributed to the successful implementation the YATI system. The latter will describe the technical performance of the YATI components and systems and evaluate the operating protocols. A variety of data collection activities will be used to evaluate each YATI information service and their collective impact on travel and traffic in and around Yosemite National Park. Surveys of system users and Park visitors will reveal the perceived accuracy, usefulness, and accessibility of information. Separate surveys are planned for the kiosk, TATS and Web page users. An exit survey of Park visitors, similar in concept to one conducted by ITS-Davis in 1994, will evaluate user responses to all YATI components. All the questionnaires are enclosed as Appendices. Pending approval of the YATI Management Board, surveys are planned for each weekend from August 2–4, 1996 through the Labor Day weekend of August 29 to September 2, 1996. Revisions, contained in this draft, to the Draft Post Implementation Evaluation Plan submitted to the Management Board in March, 1996 include the following: 1. The goal of improving air quality will not be assessed in the Evaluation Plan because it would be prohibitively expensive to do so and an operational test such as YATI is not expected to have regional air quality impacts. 2. The goal of traffic congestion reduction will be assessed using traveler ratings and perceptions of congestion; delays at the Park portals will not be quantified and National Park Service traffic counts in the Park will not be used in congestion estimation (these changes are in response to comments from virtually all parties reviewing the March 1995 Draft Evaluation Plan). 3. The schedule of data collection visits to the Region has been changed. Data will still be collected on summer weekends, but rather than infrequent and periodic visits, data collection is scheduled for 5 consecutive weekends in August through Labor Day weekend. This will allow observation of YATI operations and user response to those operations over a broader period of time and, therefore, over an expected broader range of conditions. 4. Additional questionnaires will be distributed by "intercept" of visitors to YATI kiosk locations in an effort to survey travelers in the Yosemite region who may not travel to the Park, either because it was never in their original travel plans or because information provided by YATI redirected them away from the Park.