“In addition, staying upwind and increasing fresh air ventilation in places like grocery stores, restaurants and schools can help to reduce the exposure risk.

Cliff also conducted computer modeling of school buses and found that opening windows on school buses increased ventilation and reduced exposure risks. Specifically, to achieve sufficient ventilation, at least two sets of windows should be opened, one near the front of the bus and one near the back of the bus.”

https://www.sandia.gov/news/publications/labnews/articles/2021/05-07/sneezes.html