At a toll gate of the Beijing-Hong Kong-Macao Expressway 45 kilometers south of downtown Beijing, China's capital, the flow of inbound cars began to pick up at 06:00 in the morning.
Thick morning haze has dropped visibility on road from 500 to 300 meters, which will likely to worsen the upcoming traffic rush, according to the expressway administration.
The administration has opened all the 25 lanes through the toll gate to enable the cars passing faster. However, a massive congestion which was estimated to arrive at noon is unlikely to be avoided with the growing car flow, said the staff.
Beijing's traffic monitor says that 125,500 cars have entered the city as from 06:00, a 10 percent-growth in amount of cars entering the city during the same time period one year earlier.
Other main Chinese cities also reported "moderate but steadily growing" car flow on their expressways.
The Beijing-Hong Kong-Macao Expressway on Tuesday saw a monster traffic congestion at its toll gate at the Beijing-Hebei Province border.
Bird's eye view photos shot above the toll gate showed a backup line of vehicles stretching for over 100 meters.