Tuck School of Business, Dartmouth College, Hanover, NH 03755;
Tuck School of Business, Dartmouth College, Hanover, NH 03755.
Proc Natl Acad Sci U S A. 2021 Mar 16;118(11). doi: 10.1073/pnas.2019225118.
We examine how operational changes in customer flows in retail stores affect the rate of COVID-19 transmission. We combine a model of customer movement with two models of disease transmission: direct exposure when two customers are in close proximity and wake exposure when one customer is in the airflow behind another customer. We find that the effectiveness of some operational interventions is sensitive to the primary mode of transmission. Restricting customer flow to one-way movement is highly effective if direct exposure is the dominant mode of transmission. In particular, the rate of direct transmission under full compliance with one-way movement is less than one-third the rate under two-way movement. Directing customers to follow one-way flow, however, is not effective if wake exposure dominates. We find that two other interventions-reducing the speed variance of customers and throughput control-can be effective whether direct or wake transmission is dominant. We also examine the trade-off between customer throughput and the risk of infection to customers, and we show how the optimal throughput rate drops rapidly as the population prevalence rises.
我们研究了零售店客流量的运营变化如何影响 COVID-19 的传播速度。我们将客户移动模型与两种疾病传播模型结合起来：当两个客户近距离接触时的直接接触，以及当一个客户处于另一个客户后面的气流中时的唤醒接触。我们发现，一些运营干预措施的有效性对主要传播模式敏感。如果直接接触是主要传播模式，限制客户单向流动非常有效。特别是，在完全遵守单向流动的情况下，直接传播的速度不到双向流动的三分之一。然而，如果唤醒接触占主导地位，引导客户单向流动则无效。我们发现，另外两种干预措施——降低客户速度方差和吞吐量控制——无论是直接还是唤醒传播占主导地位，都可能有效。我们还研究了客户吞吐量和客户感染风险之间的权衡，展示了随着人群流行率的上升，最佳吞吐量率如何迅速下降。
