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Abstract: |
Decision Support Systems (DSS) are a class of Information Systems that support decision-making processes and activities by the use of interactive computer-based systems and existing data, documents, knowledge, models, communication technologies, etc. This study formulates three possible web-based DSS models that can be used to help transportation engineers and toll operators in making decisions regarding the efficiency and calibration of highway toll plazas. These models are the static DSS model, the dynamic DSS model, and the hybrid DSS model. The capability of handling real-time dynamic traffic data (or the absence of such a capability) is the main reason behind the distinction between these three DSS models. In each of these architectures there are two important components, namely, DSS maps and DSS Capacity Analysis Tables (or DSS Forms). The DSS maps component consists of the entire graphical map of the OOCEA (Orlando Orange County Expressway Authority, Florida) network of toll roads with several layers and is deployed on the Internet using ESRI???s ArcIMS???s web deployment capabilities. The DSS tables are extensions to these maps and provide a tabulated collection of traffic- and segment-information on any given five highway segments that are user-modifiable. The static model is fully implemented using relational database systems like Oracle and Microsoft FoxPro, mapping components like ArcGIS and ArcIMS, toll capacity calculating models like TNCC and SHAKER, and the efficient use of programming and interfacing components like Java, Enterprise Java, HTML, SQL, etc. A preliminary implementation of the dynamic model has also been completed; the real-time traffic database being simulated by using pseudo random number generators provided by Java. The thesis also provides other information and future directions for the design and usage of more efficient implementations of the dynamic and the hybrid DSS models. |
