As traffic across the U.S. and the rest of the world has gone down during the coronavirus pandemic, it has not created much of a difference for pollution. The air is clearer, but ozone pollution decline has not been consistent with what early beliefs portrayed. Environmental Protection Agency data has shown that in some cities where there has been a significant decline in traffic, there is almost no change in ozone pollution, only a change in smog. In the vast majority of places, pollution decreased by 15% or less, meaning vehicle usage is not as big of a factor in pollution as we previously thought. Improving air quality will take more than just getting rid of big cars and trucks.