In its first six months, New York City’s controversial congestion pricing scheme has reduced air pollution by 22% in Manhattan’s toll zone, while improving air quality across the entire metropolitan region, according to new research.

The Cornell University study analysed data from 42 air quality monitors throughout the New York area between January 2024 and June 2025, tracking PM2.5 concentrations before and after the January 2025 launch of the Congestion Relief Zone (CRZ).

The findings provide the first rigorous evidence that charging drivers to enter Manhattan’s core delivers substantial public health benefits.

Within the CRZ, which covers Manhattan streets at or below 60th Street, average daily peak concentrations of PM2.5 dropped by 3.05 µg/m³. For context, background pollution levels in the region typically hover around 8-9 µg/m³, making this reduction particularly significant for public health.

Notably, the benefits were found to extend far beyond the toll zone itself. Across New York City’s five boroughs, pollution levels fell by an average of 1.07 µg/m³, while the broader metropolitan area saw reductions of 0.70 µg/m³. This refutes claims that congestion pricing merely pushes traffic and its associated pollution to neighboring communities.

The improvements grew stronger over time, suggesting drivers are increasingly adapting their behavior. In the CRZ’s first week, pollution reductions within the toll zone averaged just 0.8 µg/m³. By the 20th week, that figure had grown to 4.9 µg/m³, suggesting commuters were switching to public transit, rescheduling trips or finding alternative routes.

Indeed, traffic data supports this. Between January and June 2025, vehicle entries into the toll zone dropped approximately 11% overall, with heavy-duty truck traffic falling by 18% and passenger cars declining by 9%. The disproportionate reduction in truck traffic appears particularly important, as these vehicles contribute heavily to urban air pollution despite representing a smaller share of total traffic.

The results exceed outcomes from similar programs in European cities. Stockholm’s congestion pricing reduced air pollution by 5-15% over several years, while London’s Ultra Low Emission Zone achieved roughly a 7% citywide decline. The researchers suggest that New York’s comparatively larger impact reflects the city’s exceptional transit infrastructure and the high volume of discretionary trips that drivers can easily shift to subways and buses.

The findings arrive as other American cities, including San Francisco and Los Angeles, consider implementing their own congestion pricing systems. New York’s experience suggests such programs can deliver rapid environmental benefits while generating revenue for transit improvements – a dual outcome that urban planners have long sought but rarely achieved.

Senior author Oliver Gao said: ‘Our overall conclusion is that congestion pricing in New York City, like many other cities in the world that have implemented it, helped not only improve traffic, but also helped reduce air pollutant concentration, improve air quality and should be good for public health.’

The study’s co-lead author Timothy Fraser added: ‘It’s really exciting to me that air quality improved throughout the entire metro area. This tells us that congestion pricing didn’t simply relocate air pollution to the suburbs by rerouting traffic. Instead, folks are likely choosing cleaner transportation options altogether, like riding public transportation or scheduling deliveries at night. This thins traffic and limits how smog compounds when many cars are on the road.’

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