Health Department to Use New York City Community Air Survey to Evaluate the Impact of Congestion Pricing

Less traffic is good for public health

February 21, 2025 — The New York City Department of Health and Mental Hygiene Department (DOHMH) released today the methodology for measuring air quality changes from congestion pricing. DOHMH is working with the New York City Department of Transportation (DOT) and the Metropolitan Transportation Authority (MTA) to evaluate this innovative initiative, which will be good for public transit, and public transit creates health.

For the evaluation, air quality data is collected from the “Central Business District,” as well as from six highway corridors in adjacent areas highlighted in the MTA’s Final Environmental Assessment. Those areas have long contended with high concentrations of air pollution sources, like truck traffic and industry, and monitoring will enable an evaluation of the potential impact of congestion pricing on air quality. The monitoring effort is an expansion of the New York City Community Air Survey (NYCCAS), the monitoring network run by the New York City Health Department and Queens College, and the largest urban neighborhood air quality surveillance system in the country. DOHMH completed collection of one year of baseline data in December 2024, which will be compared to data being collected since the launch of congestion pricing on January 5, 2025. The evaluation will last two years, and the MTA will releasean annual report with initial findings in early 2026 as required by NYS law.

“A strong and safe public transit system makes our city better,” said Acting Health Commissioner Michelle Morse. “The Department of Health and Mental Hygiene will be providing data to support our state partners in their analysis. Public transit is essential for a healthy, productive, and equitable city."

DOHMH is working closely with DOT and MTA to evaluate changes in traffic. Analysts will look at periodic traffic counts from before and after the start of congestion pricing on highways near the air quality monitoring sites to see whether traffic volume has changed. Traffic and air quality patterns vary greatly by season, so a robust analysis requires approximately one full year of data both before and after the start of congestion pricing.

NYCCAS began in 2009 and has more than 80 air quality monitoring sites throughout the city. The NYCCAS program releases an annual report of air quality changes over time across neighborhoods and the most important local pollution sources, most notably vehicle and building fuel combustion. The existing NYCCAS network of neighborhood samplers and eight real-time PM2.5 monitors are well-placed to evaluate potential changes in and around the congestion pricing zone and, with funding from Project Sponsors, additional monitoring has been added to six highway corridors:

• Brooklyn-Queens Expressway
• FDR Drive
• SI Expressway
• Trans Manhattan Expressway
• Major Deegan Expressway
• Cross Bronx Expressway

The evaluation will also monitor the Van Wyck Expressway corridor to provide comparison data at a site that is not expected to see changes from Congestion Pricing.  The Health Department has created a methodology document (PDF).

New York City’s air quality is influenced by a range of factors, including weather, emissions from transportation, buildings and commercial cooking, as well as power plants and wildfires in other parts of the United States. Fine particles (PM2.5) are among the most harmful pollutants. Long-term exposure to PM2.5 contributes to an estimated 2,000 excess deaths from lung and heart disease each year in NYC (1 out of every 25 deaths in NYC), and short-term exposure can worsen respiratory diseases like asthma and other health threats.

“Congestion pricing is reducing traffic on our clogged streets, speeding up buses for hundreds of thousands of commuters, and clearing up gridlock so first responders can get to emergencies,” said Allison C. de Cerreño, MTA Bridges and Tunnels Chief Operating Officer. “We are pleased that the NYC Health Department is working with us to quantify the program’s effect on air quality. We look forward to seeing the results when they are available.”

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MEDIA CONTACT: Shari Logan: PressOffice@health.nyc.gov