Outline

Please click here to download a copy of the thesis. (File size is app. 4.0 Megs)

The purpose of this project is to develop a digital representation of the Montreal CMA street network in order to run accurate traffic assignment simulations. The accuracy of the model depends on the quality of the travel time and capacity information that is attributed to each link in the network.

To run the model, the computer requires a matrix of trip origin and destination pairs. For each trip in the matrix, the computer finds the path that minimizes travel time. The travel time and capacity variables of each link are fed into a volume-delay function which calculates the amount of time required to traverse a section of road when it is occupied by multiple vehicles. The new link volumes are used to compute new link travel times and then the entire process is repeated.

The picture above is a typical result of the traffic assignment model after 25 iterations. The area shown is central Montreal with the St. Lawrence River on the right side and the Décarie and Métropolitain freeways visible on the left. The colours indicate the level of congestion based on the volume to capacity ratio and the band widths describe the number of vehicles using each link.

How good is the model? As expected, the highest volumes are on the highways and the worst congestion is on the bridges. It's a preliminary result but it already reflects, in a general way, the reality of Montreal traffic.