Abstract
This paper analyses the major factors affecting the length of urban work trips. Evaluation of travel data from a number of Cities in the United States and Canada revealed that trip length is primarily related to the size and physical structure of the urban area, characteristics of the transportation network, and various social and economic factors. some of these concepts were also investigated through the use of simulation studies. This research has shown that, to improve work trip forecasting procedures and understand travel behaviour, the income of the trip maker, the mode of travel, the peak hour travel characteristics, and the opportunity distribution should be taken into consideration.