Authorities in the Indian capital on Monday introduced the "odd-even" car rationing scheme in a bid to cut hazardous air pollution shrouding the city.
Officials said cars with even and odd number plates will be allowed on roads on alternate days until November 15.
It's still unclear if the scheme, which was introduced in 2016 and 2017, was effective in combatting air pollution.
Uber and Ola, however, have been exempt from the plan, with the ride-hailing firms announcing they wouldn't hike prices during the period.
Meanwhile, all schools in the city have been ordered to shut down, and construction work stopped.
A government monitor on Sunday showed air quality had hit 494 on a scale of 500.

US envoys arrive in Qatar as mediators work to revive Iran talks
Two dead after wildfire guts house in northern Greece
Afghanistan launches airstrikes on IS targets on border with Pakistan
Bangladesh warns of dengue surge as weather aids spread
Fourteen children killed in Pakistan after tutoring centre roof collapses
Supreme Court rejects Trump bid to restrict birthright citizenship
South Africa's anti-migrant protesters march nationwide
Iran and US agree to halt attacks, uncertainty over Doha talks
