Chapter 32: Design and Analysis of Transport Networks

Traffic congestion in urban areas is an urgent and tangible problem impinging on our society and the lives of each of us as individuals. This problem will become increasingly serious as traffic demands rise, leading to travel delays, increased fuel consumption, severe air pollution, etc. Therefore, it is vitally important to carefully design and control transportation networks in order to provide an efficient and reliable level of service for users. Broadly speaking, network design problems refer to the optimal selection of various alternatives to improve the performance of the transportation system under certain budget constraints, including, as examples, road capacity expansion, road pricing, and traffic signal control. Financial investment on link capacity expansion is a direct, traditional way to mitigate traffic congestion; road pricing has long been recognized as an efficient means for travel demand management; and by optimizing signal settings, traffic engineers can provide smoother movement of traffic flow and enhance the reserve capacity of a signal-controlled road network.