To ease smog in Paris, an 'odd' solution

Beset by air pollution, Paris will seek to nearly halve the number of cars on the road on Monday. 

FILE PHOTO - In this March 2014 photo, the Eiffel Tower, is photographed through the smog in Paris. Paris police have lowered speed limits and ordered a halt to trash burning Wednesday, March 18, 2015 as part of emergency measures triggered by a spike in air pollution — months before the city hosts a major international climate conference.

Jacques Brinon/FILE/AP

March 22, 2015

After smog blocked out the view of the Eiffel Tower, authorities in Paris have announced that, at least for Monday, they will bar half of the city's drivers from the roads. 

According to a decree from the office of Paris's mayor, only cars with odd-numbered license plates, as well as cars with at least three passengers and all electric and hybrid vehicles, will be permitted to drive in the city.

Additionally, Paris is making public transportation free for all riders. Members of the city's electric car-sharing program will get one free hour, and everyone will get a one day subscription to the city's bike-sharing program.

"I am delighted the state has agreed to put in place a partial driving ban on Monday, which I have been requesting for several days," Paris mayor Anne Hidalgo wrote on Twitter.

The ban was prompted when Airparif, a nonprofit tasked by the French government to monitor air quality in and around Paris, predicted a return to what are considered dangers levels of PM10 ,that is particles with a diameter no bigger than 10 microns, or 10 millionths of a meter.

The World Health Organization's guidelines, issued in 2005, call for an annual PM10  mean of no more than 20 micrograms of per cubic meter and a 24-hour mean of no more than 50. On Friday, PM10 , levels in the Paris region exceeded 100 micrograms per cubic meter.

Plume Labs, which monitors air quality in dozens of cities worldwide, found that at one point last week, Paris had the world's dirtiest air, according to the Associated Press. Other cities in Northern France are also instituting various restrictions to cut pollution. 

Quartz notes that Paris has imposed similar restrictions twice in the past, most recently in March last year. Traffic decreased by roughly 18 percent and pollution particles measured fell by 6 percent.