A systems engineering approach to a methodology and mathematical model for identifying the most critical links of highway systems

In today's world, systems are more complex and interconnected with each other than ever before. The United States (US) 13 Critical Infrastructures (CIs) is one example of such a system that consists of elements such as energy, finance, government, water, and transportation. These systems, in addition to being extremely complex, are also highly interconnected and are in a continuous state of change.; This research focuses on the transportation infrastructure and specifically on highway systems. Using a systems engineering (SE) approach, a methodology and mathematical model was developed for analyzing the US highway systems to determine the critical links, i.e., those highway segments that if disrupted would have the severest effect on highway system performance. The motivation of this research was the need to identify efficiently and effectively the critical links of a highway.; The Statement of Need (SoN) formulated is to be able to find the most critical links of a highway system. The associated requirements include (1) finding the most critical link 100% of the time, (2) finding the top 10% critical links 50% of the time, and (3) finding them in a specified time. As a result, three benefits emerged from this research. The first benefit is that decision makers (DMs) could use the methodology and model to identify the critical links for analyzing the effects of unavailable highway links due to natural or manmade events. Natural events include floods, storms, hurricanes, and earthquakes. Manmade events range from accidents to terrorist acts. The second benefit is that the methodology and model is simple to use such that individuals with basic computer skills could use it. This enables DMs and analysts as well to perform highway analysis and planning from a systems' perspective. The third and most important benefit is that this methodology and model shows that the SE process is vital for highway planning and analysis. It demonstrates that this type of approach is necessary to determine the genuine effects that a disrupted highway link has on the highway system.; My original contribution to the body of knowledge for analyzing the transportation infrastructure is the use of a SE approach. The foundation of the SE approach is a methodology and mathematical model to identify the most critical links of a highway system. This is useful for highway planning and analysis purposes. For design planners and highway traffic managers, this tool allows them to take steps necessary to identify and reduce disruptions at important highway links. This in turn helps to ensure the continuous flow of traffic and the effective use contingency resources to optimize traffic flow as well.; The second aspect of my contribution to analyzing highway infrastructures is development of an assessment tool, methodology and mathematical model, more efficient and less resource intensive than current computer simulation tools. Individuals with analytical skills can use this tool for highway analysis without having to invest resources to purchase high-end computers and simulation models. In addition, this tool could be used to analyze simple to complex highway systems.