It was recently announced that Central Park, in the heart of New York City, will be closing its roads to cars and traffic in favor of making the park more friendly for pedestrians wanting to make use of the city’s historic green space.
While the main east-west transverses allowing traffic to pass from one side of the city to the other will remain open to vehicles, the rest of the roads in the park will soon be reclaimed by pedestrians and cyclists.
Although you can read about the decades-long activism to get this change passed in many other places, over here at BreezoMeter, we’re interested in what this means for air quality in the city, and in the park itself.
Wondering how many people visit the park each year? There are more than 40 million visitors to the park every year, on foot, bicycle, walking dogs, running, strolling with kids, and even riding in the iconic horse-drawn carriages.
The speed limit for cars in the park is 20mph (about 32kmh) and thousands of cars drive through the park on a daily basis.
Car Pollution: How does traffic contribute to air pollution?
Vehicles emit nitrogen oxide (NO), carbon monoxide (CO), and other pollutants like particulate matter (PM2.5, PM10) which all negatively affect people’s health. For example, exposure to NO may cause increased bronchial reactivity in patients with asthma, lung function decline in patients with COPD and increased risk of respiratory infections, especially in young children. Certainly when people go to a big, green park, even if in the middle of a major metropolis, this is not the kind of risk they want to expose themselves or their children to.
Different hours, different seasons - Air pollution is dynamic
As can be seen in this video showing the air pollution heatmap of NYC’s prized central park in the middle of the frame, air quality changes significantly over the few days this video illustrates. With the intuitive color-coding, you can see how different times of the day have different levels of pollution, usually with the peaks during the middle of the day and lower levels of air pollution at night.
One of the things this video shows, however, is that just because you’re in a park, you are not in a bubble, segregated from the rest of the city’s air. That is to say that air pollution is dynamic and moves and comes in to the park from the surrounding city streets, and likewise can leave the park as well.
The dispersion of air pollution is complicated, and is dependent on many factors such as weather and wind, surrounding topography with influencers such as building heights, and more.
What might the reduced car pollution mean for the lungs of park goers?
It is likely that the decision to stop traffic in the park is multi-dimensional, and not simply an effort to create cleaner air for park visitors. For example, the park will be much safer for pedestrians and bikers, once there aren’t cars on the road. Even with a modest and enforced 20mph (32kmh) speed limit, there were still accidents.
What is certain, is that when its emission source, for example the tailpipe of a car, is right next to a person, that person is exposed to the harmful pollutants. This said, by eliminating or at least reducing vehicular traffic in the park, thereby reducing traffic pollution, there will at least be a super hyperlocal effect on the people who otherwise would be right next to the cars during their park outings.
On a broader look at the air pollution, pollution can still come into the park from surrounding areas and can influence park visitors. So generally speaking, it is relatively unlikely that air quality in the park as a whole will be significantly improved due to the change. Again, this is because pollution crosses city streets and even continents and whole oceans, so closing a few streets in the middle of the city will likely only moderately affect people on those streets, since they are also still exposed to pollution from the surrounding streets.
There are, however, more questions that arise. For example, by decreasing traffic in the park, could there potentially be decreased traffic in the surrounding areas? Due to the changes, will the city government enhance public transportation options? Maybe closing the roads in the park to cars will just increase traffic elsewhere, ultimately increasing traffic jams and air pollution around the park, which then enters into and disperses throughout the park.
There is no way to know exactly what the effect on air contamination and air pollution levels will be, and certainly the effects will be different as the weather and seasons change, as well as people’s behavior.
The decision to reclaim the park for pedestrians and riders is one that is a long time coming. The park originally opened in the 1850’s, when the roads were designed so as to avoid horse and carriage races on straightaways. A lot has changed since then, and New Yorkers and visitors will no longer need to contend with cars on their roads. It’s back to non-motorized enjoyment in the park for now.
Read more about how BreezoMeter can help improve awareness of urban air quality in your own city.
Interested in integrating air quality data in your product or app? Talk with one of our air quality experts.