If you're taking a taxi or rideshare during the Covid pandemic, or driving with someone not in your household, wearing a mask and rolling down the windows are the best things you can do to reduce transmission of the virus. Now a new study has identified which windows you should roll down in the car to provide the most protection.
According to the findings, opening the window farthest from where you're sitting in the car provides the most airflow and protection to the driver and passenger in a car. For example, the Centers for Disease Control suggests that people sit in the rear seat diagonally across from the driver. In this case, a driver in the front left seat of a car should open the front right window, and a passenger in the back right seat should open the back left window.
Researchers from the University of Massachusetts Amherst and Brown University used a computer model to simulate a Toyota Prius driving 50 miles per hour, with a driver in the front left-hand seat and a passenger sitting in the rear right-hand seat. They analyzed the air changes per hour in six different windows open scenarios, and assumed that the air-conditioning was on in all of them.
Opening all of the windows resulted in the best air flow, but that's not necessarily comfortable, particularly in cold weather.
Interestingly, the helfpulness of the air flow provided from opening the front left and back right windows (i.e., the same windows where the passengers were sitting rather than the opposite windows) was "barely higher" than the scenario where all of the windows were closed, the study authors wrote. Opening a third window also had little effect on the helpful airflow.
Another reason why opening the opposite windows is so effective? The stream of air that enters the back left window and exits the front right window essentials acts as an "air curtain," that separates the passenger and driver, the study authors wrote.
Ultimately, keeping the windows down is just one safety step to remember when you're in a taxi or rideshare or driving with someone outside of your household. It's important to avoid getting in the car with an unmasked person outside of your household, practice good hand hygiene and try to minimize the surfaces that you touch inside the vehicle.
Rideshare platforms Uber and Lyft encourage passengers to roll down the windows as a precaution. The CDC also recommends that drivers install a partition between the passenger and driver, something that was not covered in this new study.
Covid-19 is primarily spread through respiratory droplets when an infected person talks, breathes, coughs or sneezes.