Une Journée Sans Voiture – Paris Will Go Car-Free in September

On September 27th, Paris will have une journée sans voiture (a day without car). For the first time, no motorized vehicles will be allowed to drive in the city, except for ambulances and other essential vehicles.

Heavy Traffic on the Champs Elysees in Paris (1962) by Don O'Brien. CC2.0

Join Our Community of Science Lovers!

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


On September 27th, Paris will have une journée sans voiture (a day without car). For the first time, no motorized vehicles will be allowed to drive in the city.* In addition to providing some amazing picture-taking opportunities, this car-free day could show us how dramatic shifts in city transportation networks could impact urban air quality.

Like many other cities, Paris has struggled with air pollution. In 2014, local pollution levels were so high that the government temporarily removed public transportation fees and partially banned cars from the roads. According to data released by Airparif, this response led to a drop in Paris road traffic of 18% and 6-30% drop in air pollution levels.

According to Paris Mayor Anne Hidalgo, on September 27th:


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


Paris will be completely transformed for a day. This is an opportunity for Parisians and tourists to enjoy the city without noise, pollution and therefore without stress.”

The majority (51%) of overall particulate matter (PM) air pollution in the Paris region comes from transportation. This type of pollution is a mix of liquid and solid particles that can contain sulfates, nitrates, ammonium, carbon, metals, and an array of allergens. The World Health Organization (WHO) has set recommended concentration levels for PM air pollution to avoid the potential negative health impacts of different pollutants (including asthma and other respiratory illnesses, lung cancer and cardiopulmonary disease). Globally, an estimated 800,000 early deaths occur each year as the result of combustion-related air pollution.

Arc du Triomphe in Paris at night by Duncan Hull - CC2.0

*except a few essential vehicles, such as ambulances

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American

Subscribe