Vehicles on a road in Beijing, Sept 17, 2013. [Photo/Xinhua]

In a new effort to reduce car emissions, Beijing authorities launched a campaign to encourage vehicle owners to drive less by offering cash rewards.

Car owners in the city can receive a "red envelope" worth 0.2 to 0.7 yuan (3 to 10 cents) on the instant messaging app WeChat if they leave their car parked for 24 hours, reported Beijing News.

Vehicle owners upload photos of the mileage on their odometer at the end of one trip and at the beginning of their next trip at least 24 hours later to get a reward.

The campaign - "I volunteer to drive a day less each week" - began on Sunday, which marked the National Low-carbon Day. The initiative was led by the Beijing Municipal Development and Reform Commission.

Car owners with Beijing license plates should register with the mini-app Beijing Motor Vehicle Voluntary Carbon Reduction Trading Platform on WeChat.

In addition to "red envelopes", e-coupons will be provided to motorists who leave their cars at home. On heavily polluted days, the reward is doubled. The carbon emissions reduced will be put into the city's carbon-trading market for purchase by large polluters to offset their carbon footprints.

Car emissions are a major source of air pollution in the capital city, which had 5.7 million vehicles at the end of 2016.

The city has adopted a series of measures in recent years to curb the rapid growth of vehicles and reduce carbon emissions. 

During the 2008 Beijing Olympic Games, private vehicles were banned from hitting the road on certain days based on whether their license plates end in odd or even numbers. Another driving ban based on license plate numbers has become permanent.

The city also introduced a lottery system in 2010 for local residents who want to own a car.