Officials in Tuesday declared that only cars with even-numbered registration could be used in Paris and 22 surrounding towns on Tuesday, bowing to a call by mayor Anne Hidalgo last week.
This is the fourth time the French capital has taken the measure.
Travel on the metro and other public transport was free, to encourage motorists to leave their cars at home, as was the Vélib bike hire scheme, while the Autolib electric car scheme was free for an hour.
On Monday heavy goods vehicles were banned from passing through the Ile de France region, unless they were delivering or picking up there and speed limits were reduced by 20 kilometres.
The measures will be extended on Wednesday, with even-numbered registrations banned, if the pollution levels remain high.
Motorists who ignore the rule can be fined 22 euros on the spot or 35 euros if they pay later and repeat offenders can have their cars immobilised or seized.
Green Party councillors in Lyon demanded that vehicle restrictions be introduced there, too.
Cold weather, lack of wind to blame
Weather-watchers Airparif blame an increase in the use of wood-burning stoves and other combustibles because of the cold weather and a lack of wind, which would usually disperse the polluting particles.
Another effect of the cold is that the fall in ground temperatures at night while the air above remains warmer traps pollution that would usually be disperseed.
Motor vehicles also contribute, the reason for tightening speed limits, as do electricity generators and fires set to clear brush in rural areas.
Both Paris and Lyon are soon to enforce anti-pollution stickers for vehicles and Paris this year banned old cars from its streets, as well as closing roads along the banks of the river Seine.
Air pollution kills 48,000 people a year in France and 34,000 of the deaths are avoidable, according to study published this year.