On November 13, 2014, the Beijing Environmental Protection Bureau stated that the measures taken during the APEC period to reduce air pollution brought blue skies to Beijing (APEC blue). According to its press release, during this period, PM2.5 particles were reduced by over 30 percent on a daily basis in Beijing and its neighboring regions. Since there were fewer cars on the road, the automobile speed in Beijing went up from 22 km per hour to 50 km per hour.
Construction sites were shut down from November 3 to 12. Factories which released a high concentration of pollutants were temporarily closed. The use of privately owned automobiles was subject to daily restrictions based on whether the license numbers were odd or even. Lastly, Tianjin, Hebei, and other neighboring regions also cooperated temporary in helping to reduce pollution.
Source: Xinhua, November 13, 2014
http://news.xinhuanet.com/2014-11/13/c_1113239432.htm