In an effort to cut gridlock and pollution in Guangzhou, authorities in the capital city of Guangdong province began a one-year trial program on Sunday that will cap the number of new automobiles hitting the streets, according to the state-owned Xinhua news agency.

Officials will allow just 10,000 passenger vehicles to be licensed each month, meaning only 120,000 of them will be registered during the next year, Xinhua reported.

Car dealerships were packed with customers as residents rushed to purchase cars before the start of the quota system, Xinhua said.

At rush hour in Guangzhou, average speeds are now 20 kph (12.4 mph), and it is anticipated they will become even slower, Xinhua reported.

Both Beijing, the capital of the country, and Guiyang, the capital of Guizhou province, already have limits on passenger-vehicle registrations, Xinhua said.