The purpose of this research is to examine several aspects of the San Antonio automated vehicle identification (AVI) system, including the reliability and accuracy of the AVI system, travel tag level of market penetration (LMP) trends, and a comparison of aggregated travel time values with probe vehicle travel time values. This thesis serves as a first step toward the modeling of AVI systems in which the effects of travel tag LMP, AVI reader density and AVI reader location are analyzed. GPS units were first tested as a suitable benchmark for validating AVI reliability and accuracy. A two-part system reliability study was then performed, consisting of overall system reliability and a controlled evaluation of selected AVI reader sites. The accuracy of AVI travel times was also assessed. A LMP analysis was then performed to serve as a reference parameter for the aggregate travel time study. Lastly, the level of aggregation analysis attempted to quantify differences between the individual test vehicle travel times and aggregated travel times of all observed, tag-equipped vehicles. Overall system reliability was found to be greater than 90%. The controlled reliability study showed that freeway AVI readers slightly outperformed arterial readers for correct tag capture, while total tag capture exceeded the system design parameter of 80%. Tag capture rates were found to be independent of test vehicle speed. The LMP of travel tags at a selected reader site was found to be approximately 0.5% from the morning through the evening peak. Lastly, 5-minute travel time aggregations provided a better estimate of individual test vehicle travel times than 2-minute or 15-minute aggregations. / Master of Science

This thesis presents the use of microscopic traffic simulation models to evaluate the effects of operational-level transportation projects such as ITS. A detailed framework outlining the construction and calibration of microscopic simulation models is provided, as well as the considerations that must be made when analyzing the outputs from these models. Two case studies are used to reinforce the concepts presented. In addition, these case studies give valuable insight for using the outlined approach under real-world conditions. The study indicates a promising future for the use of microsimulation models for the purpose of evaluating operational-level projects, as the theoretical framework of the models is sound, and the computational strategies used are feasible. There are, however, instances where simulation models do not presently model certain phenomena, or where simulation models are too computationally intensive. Comprehensive models that integrate microscopic simulation with land use planning and realistic predictions of human behavior, for instance, cannot practically be modeled in contemporary simulation packages. Other than these instances, the largest obstacles to using simulation packages were found to be the manpower required and the complexity of constructing a model. Continuing research efforts and increasing computer speeds are expected to resolve the former issues. Both of the latter concerns are alleviated by the approach presented herein. Within the approach framework detailed in this thesis, particular emphasis is given to the calibration aspects of constructing a microscopic simulation model. Like the simulation process as a whole, calibration is both an art and a science, and relies on sound engineering judgement rather than indiscriminate, formulaic processes. / Master of Science