Abstract In January 2025, New York City became the first U.S. metropolis to implement cordon-based congestion pricing, establishing a toll zone in Manhattan’s core. The zone, which covers all local streets and avenues at or below 60th Street, is designated the Congestion Relief Zone (CRZ). While cordon pricing is theorized to reduce traffic and improve health, rigorous causal evidence in the U.S., particularly with environmental justice considerations, has been limited. To address this gap, we evaluate short-term impacts using daily PM 2.5 data from 42 air quality monitors across the New York City metropolitan area, spanning 518 days and 17,758 observations. For the analysis, we divide the study area into three spatial units: the broader metropolitan area (Core-Based Statistical Area, CBSA), the five boroughs of New York City, and the CRZ itself. Using predictive models that incorporate meteorology, baseline pollution, and neighborhood demographics, we estimate counterfactual air quality for each station-day and compute treatment effects. We find that average daily maximum PM 2.5 concentrations declined by 3.05 μg/m 3 (SE = 0.022) within the CRZ during the first six months. This represents a 22% reduction from a projected average of 13.8 μg/m 3 without the policy. Effects extend beyond Manhattan: average declines across New York City’s five boroughs were 1.07 μg/m 3 (SE = 0.006), and the broader CBSA saw reductions of 0.70 μg/m 3 (SE = 0.004). Moreover, treatment effects in the CRZ grew over time, rising from 0.8 μg/m 3 in Week 1 to 4.9 μg/m 3 by Week 20, indicating accumulating behavioral adaptation. These results provide the first zone-specific, quasi-experimental evidence of air-quality improvements following congestion pricing in the United States. As other American cities consider similar policies, our findings demonstrate that cordon pricing can deliver rapid, geographically broad environmental benefits.
Fraser et al. (Mon,) studied this question.