The Hong Kong-Zhuhai-Macau Bridge Advance Work Co-ordination Group Project Office has started inviting tenders for the main bridge's preliminary design and site investigation.

The main bridge is a 29.6km dual three-lane carriageway with a 6.7km-immersed tunnel. It runs from the artificial island off Gongbei in Zhuhai, to the eastern artificial island for the tunnel section just west of the Hong Kong boundary.

Its preliminary design is expected to begin in April. The Transport & Housing Bureau said three governments are in full swing implementing the bridge project.

The feasibility study report - which the group endorsed at its November 27 meeting - will be submitted by Guangdong this month for the Central Government's consideration.