Analyzing the Role of Service Congestion in Accessibility Modeling

An important variable in measuring potential access is the competitive nature of the service being provided. Health services such as physician visits or hospital beds are often viewed as rival goods where one’s consumption of a service will diminish another’s ability to consume the same service. Congestion at facilities is as important as the overall level of supply at facilities. For rival goods, accessibility and congestion are linked as reciprocal concepts. The relationship between accessibility and congestion is even more important in the current era of the COVID-19 pandemic because critical care services, such as the need for intensive care unit beds, illustrate the need to focus on a balanced level of congestion among hospitals to prevent care failure at the local level. This research investigates the role of service congestion in various existing and proposed models and measures using data from the state of Illinois. Because evenness of service congestion and lower travel times are conflicting goals, evenness of congestion as measured by Gini coefficients is weighed against the cost of travel to determine a compromise solution. Results suggest that the rational agent access model and the congested supply accessibility model provide such compromises when used in conjunction with the transportation problem.