France deployed hundreds of police in Paris today to enforce the most drastic curbs on car use in 20 years as authorities sought to reduce health-endangering pollution days before town hall elections.
Amid concerns of a worsening air quality after a week when unseasonably balmy weather boosted pollution, public transport was free of charge while drivers with even-numbered licence plates were told to leave their cars at home of face fines.
Paris is more prone to smog than other European capitals because of France's diesel subsidies and its high number of private car drivers.
Some 700 police manned key entry points to the city from before dawn to apply the scheme, in which drivers may only use their cars on alternate days depending on whether their licence plates finished with an odd or even number.
At Porte Maillot on the West of Paris, around 20 police were looking out for offenders.
The restrictions did not apply to cars with at least three people on board to encourage car sharing schemes but also to other vehicles such as emergency services or clean vehicles such as hybrid or electric models.
Drivers who defy the curbs are fined €22 on the spot but most understand the reasons behind such an operation.
While nowhere near levels seen in some Asian cities, European Environment Agency (EEA) figures showed last week 147 microgrammes of particulate matter (PM) per cubic metre of air in Paris - compared with 114 in Brussels, 104 in Amsterdam, 81 in Berlin and 79.7 in London.
The last restricted driving scheme was introduced in 1997 in to combat pollution from heavy diesel fumes. It lasted one day.
Early reports suggested police were applying the curbs with a degree of flexibility, with exemptions allowed for many categories of vehicles including taxi cabs and hybrid cars.
The anti-smog action is being implemented days before voters elected city hall mayors across the country in a two-round ballot on March 23 and 30.
Polls show President Francois Hollande's Socialists are favourites to retain control of the French capital.