TRB 2016 Blue Ribbon Committee
16th National Transportation Planning Applications Conference

Point of Dispensing (POD) Model

Corresponding Author: Ashley Tracy, Whitman, Requardt, and Associates

Presented By: Ashley Tracy, Whitman, Requardt & Associates, LLP


The Point of Dispensing (POD) Model is a unique application of a customized evacuation model developed for DelDOT. Points of Dispensing (POD’s) are used to distribute medical countermeasures to a population during a biological hazard outbreak. Emergency planners typically focus on the internal operation of the POD, but fall short in accounting for external factors such as roadway and parking capacity. The POD Model can be used to predict how the travel network might perform in a state of emergency if the public were directed to visit a POD for an antidote.

The presentation will discuss a case study performed for Wilmington, Delaware using five POD’s at publicly accessible locations. This application of an POD model is fundamentally different than a standard evacuation model where people go from one point to another and stay; this application models people converging to the most desirable POD, waiting in line to receive medication, and being released to return home or to work once treated. The model included a destination choice algorithm, and toggles to run as a “full state of emergency” i.e. no one goes to work, or “limited” state, where non-resident workers travel as normal, and stop at a POD for treatment on the way to work. Another input is patient arrival rates. The model measures of effectiveness are POD utilization, patient wait times (average and maximum) at each POD, and volume to capacity ratios on links while accounting for parking capacity constraints. The case study pointed to over-utilized POD locations with extraordinary wait times while others were relatively under-utilized.

National security issue. The results of this application provide data for emergency planners to consider the limitations of the roadway transportation when selecting the quantity and geographic distribution of POD locations, staffing and supply allocations, and methods for assigning POD’s to residents or workers. It also points to a need to consider means to inform the public about current wait times at each POD to inform their destination choice process (through venues such as ITS, app-based, SMS, or public broadcasting), and potential parking and access management plans for highly utilized POD’s.


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