Modeling the relationships between hospital surge capacity and dynamic traffic conditions

Most existing hospital surge capacity models are focused on the problem of strategic planning or preparedness, i.e., predicting the resources required over the entire course of an incident based on a static set of inputs. The implicit assumption is that medical and public health response are not impacted by external situations, i.e., the existing models don't support tactical planning and preparedness. One of the external situations not considered is traffic. Anyone who lives or works in a major metropolitan area knows that the time of day, day of the week, or unusual circumstances such as accidents and major social/cultural events significantly impact travel time. When modeling hospital surge capacity in response to a catastrophic event, such as treatment and vaccinations for contagious diseases during a bioterrorism crisis, the impact of dynamic traffic conditions on the arrival and departure of patients at the hospital, as well as the ability of hospital staff to arrive in a timely manner to administer medical care, must be considered. As part of a Bioterrorism Crisis Management (BCM) simulation being developed as part of the National Center for the Study of Preparedness and Catastrophic Event Response (PACER), previously reported upon in paper 09S-SIW-065, researchers at the Johns Hopkins University Applied Physics Laboratory (JHU/APL) and the Florida Atlantic University (FAU) have had to consider the interactive relationships between hospital surge capacity and dynamic traffic conditions. This paper describes these relationships, as well as their implementation in the BCM simulation. It discusses the surge capacity simulations developed and employed for both medical treatment and vaccination, as well as a hybrid meso/microscopic dynamic traffic simulation that permits the application of microscopic traffic simulation techniques to areas around the treatment centers while simulating a large network in good detail with mesoscopic simulation techniques, implemented using the Aimsun traffic simulation tool.