The on-site Journey Time Indicator System at Canal Road flyover northbound, near the north portal of Aberdeen Tunnel, will be activated from Sunday.

Motorists will be able to use it to calculate travel times of different harbour-crossing routes from Hong Kong Island to Kowloon, and to decide which one is best for them.

The journey times on display are calculated from the locations of the indicators to the Kowloon exits at the tunnel toll plaza. They will be updated every five minutes, or more frequently.

The system features data acquisition, a communications network, a remote on-site LED display and a Central Control Centre. Apart from detection cameras to collect traffic data, the system has in-vehicle Global Positing System units installed on 82 buses to provide GPS data for analysis.

Journey times to Kowloon through the Cross Harbour Tunnel, the Eastern Harbour Crossing and the Western Harbour Crossing will be shown round the clock on the indicators in green, amber or red.

For routes through the Cross Harbour Tunnel, the colour ranges are:

*Green - 10 minutes or below

*Amber - 11 to 20 minutes

*Red - above 20 minutes

For routes through the Eastern/Western Harbour Crossings, the colour ranges are:

*Green - 20 minutes or below

*Amber - 21 to 40 minutes

*Red - above 40 minutes

The indicator will show a "Very Serious Congestion" sign or a "Tunnel Closed" sign when necessary. The first one was commissioned at Gloucester Road eastbound, outside Revenue Tower, last June.