The smog is expected to completely disperse on Wednesday as a strong cold front will hit the region.
Zhang Linna is the Chief reporter of the Central Meteorological Station
"The new front cold will strengthen the north wind. Then, the lingering smog will be eased under the influence of the wind."
Heavy smog hit regions like Beijing and its neighboring provinces of Hebei, Henan, Shanxi and Shandong on the weekend.
The smog came along with a travel peak on Sunday, the last day of a 3-day national New Year holiday.
The smog reduced visibility to less than 200 meters in some regions, leading to many expressways being closed in the north, east and central China.
Song Chun, a transport law enforcement official, describes highway conditions in parts of Chongqing,
"The visibility on most parts of the road is less than 50 meters, so it is not safe to travel."
Almost all major expressways linking Hebei and Beijing were closed Sunday morning.
In Shandong province, over 100 flights at Jinan Airport were cancelled or delayed.
As a result, many people have resorted to taking the train as they return from holidays.
The northwestern Xi'an Railway Station increased trains to major destinations in order to deal with the travel peak.
Wang Shanshan works at the railway station.
"In order to deal with the return travel peak, we increased additional trains to nearby cities like Baoji, Ankang and Yulin to relieve passenger flows."
According to the transport department, over 8 million passengers were expected to travel by rail, nationwide, on Sunday alone.
For CRI, this is Niu Honglin.
