A GIS based tool to determine optimal routes

Travel in urban and suburban areas is an important activity in an individual\u27s daily time budget. Each trip is preceded by a planning process for selecting a desirable or an optimal route from the origin to destination. Optimal can take many forms, such as shortest time, shortest distance, least total cost, or safest/most reliable path. Reliable paths are of interest because of the impacts of congestion on travel tomes, and the resultant variability in travel times. A model to help identify optimal travel paths based on travel time variability is developed in this research; Congestion on streets is one of the prime reasons for the variability of travel time on streets. In order to find an optimal route (based on minimizing expected travel time variability) from a source to destination factors influencing congestion were studied. Data were collected for these factors. Djikstra\u27s algorithm was used to develop a route finding application. The application considers factors related to recurrent and non recurrent congestion and their impacts on estimated travel times. Data for such factors influencing congestion were processed and used as inputs to the application. The application was tested on the street network in the Las Vegas valley as a case study