Digital signboards will be set up along three routes leading to the Hong Kong entrance of the Cross-Harbour Tunnel: on the eastbound lane along Gloucester Road near Revenue Tower, the northbound lane on the Canal Road Flyover near Aberdeen Tunnel Portal and the westbound lane of the Island Eastern Corridor, near City Garden.

The signboards will be positioned in such a way that motorists will have ample time to divert to less congested routes if necessary.

Assistant Commissioner for Transport Alex Yeung Wing-tsan said about 5 per cent of the 260,000 commuters who pass the three points each day would have their cross-harbour trip shortened by three minutes due to the system.

But there are doubts over whether the system will help ease congestion, as most traffic jams usually occur at predictable times.

Instead, calls have intensified among academics and the infrastructure industry for the government to set uniform tolls for the three cross-harbour tunnels as the best way to distribute traffic more efficiently and avoid congestion.

The operator of the Eastern Harbour Crossing, New Hong Kong Tunnel Company, has applied to raise its tunnel toll by a third to $20.