Application of conventional and simplified modeling techniques under uncertainty: a GIS-T approach for Jerusalem

This paper introduces a GIS-T based approach for travel analysis in urban areas where travel data are incomplete or fraught with high degrees of uncertainty. The approach is based on conventional and simplified modeling techniques. It considers the case of the city of Jerusalem and its vicinity, where political instability, travel restrictions, and lack of detailed transportation and socio- economic data are major sources of uncertainty for effective transportation planning. The procedure can be useful in other urban areas with little or limited travel data. The travel restrictions that have been effective in the area of Jerusalem divide the transportation system into two components applicable to two ethnic groups (Israelis and Palestinians). Key elements of the procedure discussed in the paper are the determination of a reliable origin- destination (O-D) matrix and an adequate traffic assignment method. The Urban Transportation Planning Systems (UTPS) models and simplified modeling techniques that derive O-D matrices from traffic counts are considered. Similarly, the Method of Successive Averages (MSA) and User Equilibrium are used for traffic assignment. The analysis is based on the use of Geographic Information Systems in Transportation (GIS-T). For this purpose, the transportation software TransCAD is used, as it links both conventional and simplified applications of models to GIS. The results revealed that the conventional four- step model, with the MSA used for traffic assignment, is the most adequate modeling technique among those analyzed. Last, but not least, GIS-T demonstrated to be a powerful tool in dealing with uncertainty in transportation planning.