The South Bronx Has a Pollution Issue. Congestion Pricing May Worsen It.

Preliminary data from the first few weeks of New York City’s tolling plan show a possible uptick in traffic in the neighborhood.

In addition to easing traffic, New York City’s new congestion pricing plan is expected to produce environmental benefits, including fewer greenhouse gas emissions and cleaner air.

But if motorists avoid the tolls leading into Manhattan via detours, other areas in the metropolitan region could see their air quality deteriorate.

The South Bronx, already burdened by a large number of pollution-spewing trucks that contribute to elevated rates of asthma, is of particular concern. And some preliminary data from the first two weeks of congestion pricing, which began on Jan. 5, find a possible uptick in traffic there.

Local activists, like Mychal Johnson, are paying attention. “You want to reduce congestion, please do it here, do it where we’re breathing toxic air,” said Mr. Johnson, co-founder of South Bronx Unite, a nonprofit focused on social, economic and environmental issues.

It’s still too early to draw any conclusions about traffic in the South Bronx and its link to congestion pricing. But early data from Inrix, a transportation analytics firm, showed that afternoon travel times on major highways and expressways in the Bronx had increased by 9 percent during the first two weeks after tolling started, compared with the same time period in 2024. There was also a 2 percent decrease in travel times in the mornings.

Travel times can serve as a measure of congestion, with trips that take longer indicating more traffic, but they can also reflect other impediments, such as accidents or construction projects. INRIX collected the data from devices like cellphones and GPS navigation systems.