Due [20,23]. Hans[11] enhanced the importance of the

Due to the data requirements and the complexity of urbanplanning and transportation problems, there has been a growinginterest in the use of decision support systems (DSS) to analyze themat the operational (e.g., 17,26), the tactical (e.g., 18) and thestrategic planning levels (e.g., 5,29). Adequate graphical interfacesare important to represent solutions in routing problems given theirstrong spatial component. Information and communication technologies(ICT) can play an important role for constructing toolsembedding algorithms, graphical interfaces and access to remote datathrough the Internet. Due to the spatial nature of these problems,geographical information systems (GIS) have been a natural componentof such DSS as they are important tools for collecting, organizing,and displaying spatial data in a large variety of planningapplications, such as in vehicle routing problems 20,23. Hans11 enhanced the importance of the development of GIS forurban transportation planning and modeling, including networkbasedurban transportation planning, and the incorporation ofnetwork data into a GIS framework in order to have a high-speedinteractive system suitable for providing near real-time alternativesand policy analysis. Although transportation researchhas been “late to embrace GIS as a key technology to support itsresearch and operational needs” 28, there has been an increaseof such research in recent years. Much of this research alsoincorporates exact and heuristic solution algorithms with the GIS(e.g., 1,5,12,17,19,23,26).The development of decision support tools profiting from state-ofthe-art ICT is an important avenue of research. World Wide Webtechnologies have transformed the design, development, implementationand deployment of DSS; however, it is recognized that the useof Web-based computation to deploy DSS applications for remoteaccess remains less common 3. In the field of transportation, somerecent developments can be found, e.g., Ray 21 has developed a webbasedspatial DSS for managing the movement of oversize andoverweight vehicles over highways.