A Network Simulation of High-congestion Road-traffic Flows in Cities with Marine Container Terminals

Port cities where marine cargo terminals are located are generally near urban areas characterized by high-congestion road traffic. Changes in cargo traffic volumes into a marine terminal, or in the surrounding traffic arteries, which carry this traffic, can significantly affect the terminal's operations. Conversely, activity at the terminal can have an impact on the traffic levels and congestion for a considerable distance from the terminal. This paper demonstrates a methodology useful for studying the impact of road traffic flows on marine container terminals located in highly congested areas. This model was developed at the request of the Virginia Center for World Trade and was used to answer three planning questions in the port of Hampton Roads, Virginia, USA-what would be the impact of: opening a new section of interstate highway, a projected doubling of container traffic at one terminal, and a daily unit train in the vicinity of another terminal. The problem was made more challenging by limited data-collection funds. None the less, the model was deemed valid by a panel of traffic experts and officials from several major state and private agencies involved in marine traffic management. The model results were subsequently a factor in two major decisions related to terminal management. The purpose of this research is to examine the impact on marine container terminals and their associated land-traffic flows of several proposed transportation changes in an urban area of very high-congestion road traffic. The proposed changes include road projects, modifications in marine terminal growth patterns and rates (including alterations in both the types and the volume of tonnage), and non-road changes such as rail traffic, as each might affect vehicular traffic in the vicinity of marine container terminals. In particular, the authors were commissioned by the (United States of America) Virginia Center for World Trade (VCWT), a state-of-Virginia funded organization whose purpose is to study and facilitate foreign commercial activity in the Commonwealth of Virginia. They were asked to investigate the effects of three scenarios in the Hampton Roads, Virginia, area. The first considered scenario examines the impact of a new section of interstate highway on the three marine terminals in the area, the second the addition of a daily train at a critical intersection at the entrance of one of the terminals, and the third a proposed doubling of container traffic at another of the terminals. The research project was made more challenging by the restricted budget for such activities as data collection. While localities are very concerned over the increasing congestion created by the interface of commercial and other traffic, they generally have very limited funds to expend on the study of these problems. Whereas plentiful funds would allow the collection of the type of data necessary for detailed mathematical modelling, tight data collection budgets usually allow detailed modelling only in very microscopic studies, as in, for example, studies of a single intersection or road segment. In larger studies (including this one), available data usually dictate that the modelling be more general and less mathematical, such as using average parameter values as opposed to developing detailed equations for the dynamic value