The impact of New York City's Open Streets Program on local traffic

In recent years, there has been growing popularity in urban policies that prioritize pedestrians by reallocating road space away from motorized vehicles, with a focus on active transportation such as walking and cycling, as well as public transit. However, there is limited research exploring the traffic implications of such policies. New York City's (NYC) Open Streets Program, launched in April 2020 during the COVID-19 pandemic, aimed to provide outdoor respite and expand access to public space by closing or restricting traffic on select streets. While prior research has suggested health-relevant impacts of Open Streets programs on physical activity, social cohesion, and noise, their impact on local traffic is not well understood. Therefore, we conducted a propensity score–matched difference-in-differences analysis at the census tract level using highly spatially resolved, NYC-wide crowdsourced monthly average daily traffic data. Comparing traffic for census tracts pre-implementation (2019) and post-implementation (2021) of Open Streets, we found an average 13.4% reduction (95% CI: −17.9%, −8.9%) in traffic in tracts with Open Streets compared to pretreatment levels. Moreover, we observed a reduction in traffic (−0.42%, 95% CI: −0.51%, −0.33%) with each percentage point increase in contiguous treated census tracts, suggesting that traffic reductions may be greater where Open Streets are clustered. This study offers insights into the application of a robust research method for evaluating the environmental outcomes of road space reallocation schemes. Additionally, it contributes to understanding the effectiveness of Open Streets in reducing local traffic exposure and informs policy design to create more pedestrian-friendly and healthier urban neighborhoods.