Beijing – The Chinese capital’s environmental bureau announced that Beijing removed 180,000 old and polluting vehicles from its roads in the first four months of 2017, as part of its efforts to tackle congestion and reduce smog.

An action plan published in 2015 committed Beijing to removing a total of one million ageing vehicles over the 2013-2017 period. Beijing needs to take 300,000 off the road this year to meet the target.

The Beijing Municipal Environmental Protection Bureau said the capital has a total of 5.7 million vehicles, responsible for half of the city’s nitrogen oxide emissions, a major source of smog.

Earlier this year, Minister of Environmental Protection Chen Jining said traffic is responsible for 31 percent of Beijing’s total particulate matter. The city has promised extraordinary measures this year to meet its 2013-2017 air pollution targets following a spike in smog in the region in January and February.

Average readings of small breathable particles, known as PM2.5, reached 95 micrograms per cubic meter in Beijing in the first two months of 2017, up 69.6 percent from the same period last year.

The World Health Organization recommends concentrations of just 10 micrograms.

The city aims to bring the average down to around 60 micrograms this year, a cut of more than 25 percent from 2012 levels.