The fourth harbour crossing is being proposed in Hong Kong as the fourth underwater tunnel to cross the Victoria Harbour to ease the traffic through the Cross-Harbour Tunnel. Even though the Western Harbour Crossing, operated by CITIC Pacific Limited, was built for this purpose, the tolls for crossing is double the rates of the Cross-Harbour Tunnel, proving the Western Harbour Crossing ineffective in diverting traffic from the Cross-Harbour Tunnel. Around this time, a new tunnel between North Point and Kowloon Bay was suggested to relief the stress on the Cross-Harbour Tunnel.
However, the Hong Kong government suffered from the East Asian financial crisis in 1997, and all major projects were put on hold. It was not until 2005 that the topic was brought up again, as the Eastern Harbour Crossing announced it would increase its toll prices. It was predicted that 1/3 of traffic from the eastern crossing would use the Cross-Harbour Tunnel instead as a result of the price hike, and the influx would certainly be disastrous for the already overloaded tunnel. The call for a fourth tunnel was revived to counter the problem.
A new proposal stated that the new crossing would be an immersed tube joining a reclamation site off Hung Hom with in Causeway Bay. The toll booths would be placed at the Kowloon end, and would join there. At the Hong Kong Island end there would be a major interchange located under the Victoria Park, connecting with the Island Eastern Corridor. This proposal was deemed the more likely to happen.