The coronavirus pandemic upended commuting patterns in the Pittsburgh region. In the early months of Pennsylvania’s shutdown, traffic dropped by as much as 50 percent in Allegheny County, according to Streetlight Data. On average, PennDOT officials say vehicular traffic remains about 20 percent lower than normal.
In a recent paper, a Carnegie Mellon University research group documented a drop in air pollutants. Their work showed that less driving meant lower concentrations of emissions such as carbon monoxide and nitrogen dioxide. Professor Albert Presto said more surprising was the decrease in fine particulate matter, which are really small particles that can cause big health problems.
“That was the same whether we were in a high-traffic place or a low-traffic place,” he said.