Existing state and local government systems for disseminating traveler information (major incidents, traffic conditions, road closures, etc.) may fulfill their purpose of providing localized travel information. However, these systems are often limited in the number of value-added information service providers (ISPs) that can access the information directly (fixed number of data output ports); the scope of information provided (e.g. local vs. route specific weather); and in the ability to provide information in a way that ISPs can easily re-package (i.e. tailor) the information for specific users. In addition, there is often little coordination between adjacent states or jurisdictions regarding data format or content, with the result that each traffic information system is a stand-alone operation, and it is difficult to integrate the information from multiple jurisdictions. What is needed is a method by which information from many different sources can be compiled to present a clear and commonly understood representation of travel conditions across a region, and nationally. State and local agencies should continue to collect and update travel related data, but this data should then be provided in a common, universally understood format suitable for automated processing. The United States Federal Highway Administration (FHWA) determined that the use of eXtensible Markup Language (XML) is one approach that has merit for the dissemination of traveler information in a common format. In FY01, FHWA funded an operational test of a multi-jurisdictional Advanced Traveler Information System (ATIS) using XML. The purpose of the test was to demonstrate the utility of integrating traveler information from multiple jurisdictions and to evaluate the draft ATIS vocabulary and message structure standard developed by the Society of Automotive Engineers (SAE) ATIS Standards Committee. These recommended standards were developed in ASN.1 (Abstract Syntax Notation) and released in late 1999 as SAE J2353: Data Dictionary for Advanced Traveler Information Systems (ATIS) and SAE J2354: Message Sets for Advanced Traveler Information Systems (ATIS). The test conducted by Mitretek included the conversion of the ASN.1 ATIS standard to XML, the selection of a suitable test site, the use of the XML ATIS standard to build and demonstrate a trip-based traveler information system, and the development of recommendations to change and improve the standard. The cities of Gary, Indiana; Chicago, Illinois; and Milwaukee, Wisconsin were chosen as the location of this test. These cities have formed a traffic information consortium called the GCM Corridor. The test results and recommendations were provided to the SAE ATIS Committee for consideration. Because the existing GCM information gateway provided information using a CORBA interface, the test also provided first-hand experience translating from Common Object Request Broker Architecture (CORBA)-based data to the XML vocabulary.
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