China's Jingtai expressway was closed today due to particularly heavy smog.
Video captured in Beijing on October 20 shows a car driving through thick smog in conditions of extremely low visibility.
Several police cars parked in front of a toll gate to stop other vehicles entering.
Beijing's meteorological observatory issued an orange alert - the second-highest after red - for smog, which meant visibility might be or was already lower than 200 metres.
Several motorways in Beijing have been closed.