HONG KONG, Jan. 7 (Xinhua) -- The first stage of a fast channel, namely Central-Wan Chai Bypass, to connect the western and eastern parts of Hong Kong island will be commissioned on January 20, said the Transport Department of China's Hong Kong Special Administrative Region on Monday.

The existing east-west corridor on Hong Kong Island is operating beyond its capacity with serious traffic congestion. To relive existing traffic jam, the government of Hong Kong SAR commenced the construction in December of 2009, with a cost of around 36 billion Hong Kong dollars. After its opening, the fast channel will cut down travelling time between the western and eastern parts of Hong Kong island from around 40 minutes to five minutes.

The speaker of the Transport Department, the fast channel was 4.5 km, with 3.7 km in the form of a tunnel. Besides, the tunnel of the fast channel introduced the first air purification system for use in road tunnels in Hong Kong.

The fast channel diverted part of existing traffic to underground, which allowed commuters to reach a destination directly and alleviates traffic congestion at major thoroughfares, saving about 40 million hours of travelling time each year, equivalent to 3 billion Hong Kong dollars in economic benefit.