Session 10

Two main objectives of transportation planning are to simulate the current traffic volume and to forecast the future traffic volume on a transportation network. Traffic demand modeling typically consists of the following tasks (1) defining traffic analysis zones (TAZs) based on land-use characteristics, (2) building the transportation network, (3) collecting traffic data for calibration, and (4) performing the four-step traffic demand modeling process of trip generation, trip distribution, mode choice, and trip assignment. The first two tasks used to be time-consuming because paper maps and aerial photographs were the primary tools for constructing TAZs and the transportation network. In recent years, transportation planners have used geographic information systems (GIS) to perform the tasks. A GIS is a tool capturing, storing, and analyzing spatial or geo-referenced data. It also has the additional capability in data integration, such as integration of socioeconomic and traffic data for traffic demand modeling