TIANJIN, Sept. 26 -- A total of 42,000 old vehicles were phased out in northern China's Tianjin Municipality from January to August as part of the city's environment protection campaign, local authorities said Thursday.

Old ones now account for only 18 percent of the total number of vehicles running on the streets, a decrease of 4 percent year on year, official data showed.

The government has taken measures to advance the work, including traffic control over high-emission vehicles inside the city's outer ring, offering subsidies for phased-out light-duty diesel trucks and encouraging bulk material transportation companies to use vehicles with lower emissions, said Zhang Zesheng, an official with the Tianjin Ecology and Environment Bureau.

The government will further check the vehicles on the road, inside enterprises and industrial parks, push forward the transition on means of transportation from road to rail, advance the upgrading of transportation structure and vehicles and promote mobile source pollution prevention, said Zhang.