After days of high levels of pollution in Paris, the city’s authorities attempted to halve the amount of traffic on the roads.
Only vehicles with number plates ending in odd numbers were allowed to drive on Monday.
Hundreds of police officers managed checkpoints around the French capital to check for anyone breaking the ban.
There were grumbles, but most people seemed sympathetic to the idea.
“I was driving around on a scooter last Thursday and Friday and it was really polluted. On a scooter you can really feel it, so my bronchial tubes were quite blocked. It is a good idea but it would have been better to have planned it a bit in advance so that people could prepare themselves,” said one.
Another man, driving in from outside Paris, said: “I am from Le Havre I have no choice but to come to Paris, but I’m lucky because I heard that company cars could go through with even numbers so I had to go, I had no choice. But I completely understand why they are doing this because of the pollution problem.”
Public transport has been free since Friday to encourage more people to leave their cars at home. Vehicles with three or more people are exempt as well as electric and hybrid cars.
It’s only the second time such drastic measures have been introduced in nearly two decades.
Warm daytime temperatures and cool, dry nights have left Paris with pollution levels almost twice as high as London.
The French prime minister said they were looking at whether to extend the restrictions into Tuesday, banning odd numbers.