SEOUL (THE KOREA HERALD/ASIA NEWS NETWORK) - South Korea's capital city of Seoul is waiving public transport fees Wednesday (Jan 17) during peak commuting hours as the daily average density of ultrafine dust is expected to exceed 50 micrograms per cubic metre throughout the day - a level considered "bad".

The free public transport programme - first implemented last year and initiated on Jan 14 due to air pollution - is part of the capital city's measures to fight air pollution, which also include limiting car use and temporarily shutting down government building parking lots.

A thick layer of smog that mostly came from China is expected to envelope the capital city and parts of the midwestern regions, including the Chungcheong provinces.

Rain or light snow is forecast in Gangwon Province, the eastern coastal area, Chungcheong provinces and Jeju.

Temperatures will remain at zero deg C in Seoul, Incheon and Chengju in the morning, while daytime highs are expected to be above freezing across the country.