'Congestion' is commonly cited as a major urban ill by the public, politicians and the media. Urban transportation authorities aim continuously to manage (if not altogether eliminate) the problem through a variety of measures. But what do we mean by congestion? How do we quantify it? What is its cost? Some Canadian urban areas have attempted to answer these questions. However, methods, data, approaches and assumptions have varied. A recent Transport Canada study, The Costs of Congestion in Canada's Transportation Sector, developed congestion indicators for the nine largest urban areas in Canada. The indicators were based upon data that were derived from each urban area's travel demand forecasting models. Although the models all produce the same outputs (i.e., simulations of vehicle [and other] trips), there are structural and methodological differences among them. This paper reviews these differences, as well as the points of commonality, and discusses their implications on the analysis of congestion. It explains the role of models in analyzing congestion, and provides a basis for urban authorities to conduct their own congestion analyses. The paper also provides some suggestions for further research. For the covering abstract of this conference see ITRD number E211426.
Abstract