Architecture Development for Web-Based Geographic Information System Applications in Transportation

Abstract

A geographic information system (GIS) is a computer-based system that integrates computer software and hardware to collect, store, and analyze objects and phenomena for which geographic location information is critical to the analysis. A variety of transportation management and planning applications can benefit from the abundant information contained in a GIS. Advances in information technology and the Internet enable the once resource-intensive GIS transportation application to be widely available. Transportation agencies and companies are publishing these applications on the Internet and offering travelers convenient trip-planning features and traveler information. Proposed in this paper is a three-tier architecture for implementing GIS database applications on the Internet. This architecture uses a platform-independent Java applet as the front end for the client. The Java applet can run in any Java-enabled web browser, regardless of the operating system used. This capability simplifies the deployment issue. The Java applet is also capable of performing more sophisticated computations and interactions than those of static Hypertext Markup Language (HTML) pages. Within the domain of the three-tiered information system, a middleware server is proposed to serve as the interface between the client request and the GIS database for data communication. A prototype three-tiered client server application is developed based on the proposed architecture. The client side is an interactive map applet, and the server provides a shortest-path search function and a real-time traffic information service to the client. The information request by the client is retrieved from the GIS database.