Riding in Cars with COVID-19

As public health officials warned of the dangers of congregating in enclosed spaces during the COVID-19 pandemic, Americans took refuge in one of our favorite private spaces: cars. Although traveling by car may put you at lower risk of transmission than, say, a crowded bus, private vehicles still carry their own risks of infection, reports Emily Anthes. "They are small, tightly sealed spaces that make social distancing impossible and trap the tiny, airborne particles, or aerosols, that can transmit the coronavirus."

A new study maps the patterns of airflow inside a car and suggests that "opening certain windows can create air currents that could help keep both riders and drivers safe from infectious diseases."

"Unsurprisingly, they found that the ventilation rate was lowest when all four windows were closed. In this scenario, roughly 8 to 10 percent of aerosols exhaled by one of the car’s occupants could reach the other person, the simulation suggested. When all the windows were completely open, on the other hand, ventilation rates soared, and the influx of fresh air flushed many of the airborne particles out of the car; just 0.2 to 2 percent of the simulated aerosols traveled between driver and passenger."

When opening all the windows isn't an option, the study's authors recommend opening the windows opposite each occupant to create the most effective air flow.