The first stage of the Central-Wan Chai Bypass & Island Eastern Corridor Link will be commissioned on January 20 and will significantly cut down travelling time between Central and North Point.

The 4.5 km-long bypass, with 3.7 km in the form of a tunnel, connects the Rumsey Street Flyover in Central and the Island Eastern Corridor in North Point.

Upon commissioning, it will take only five minutes to drive between Central and the corridor in North Point, making traffic flow smoother and more direct between the eastern and western parts of Hong Kong Island.

The traffic lanes of the bypass are separated by double white lines, which means change of lane is not allowed.

Drivers must plan their destination ahead of time and select a traffic lane before entering the bypass.

The project diverts part of existing traffic to underground, which allows commuters to reach a destination directly and alleviates traffic congestion at major thoroughfares, saving about 40 million hours of travelling time each year.

That is equivalent to $3 billion in economic benefit.

The bypass tunnel introduces the first air purification system for use in road tunnels in Hong Kong, which can effectively remove at least 80% of the respirable suspended particulates and nitrogen dioxide.

The scale of the air purification system is the largest of its kind in the world.