The consultancy study on how to improve traffic distribution among the three harbour tunnels will be completed in the first half of this year, Secretary for Transport & Housing Eva Cheng says.

She told lawmakers today the study will identify an option feasible in transport, financial and legal terms, adding the recommended plan should minimise the impact on public expenditure.

"The consultants are of the view the reasonable toll levels for the three crossings should be considered carefully. Excessively low tolls will attract heavier vehicular traffic and create pressure on other road networks, while excessively high tolls will not be acceptable to the public."

Given the limited capacity of the connecting road networks, if cross-harbour vehicular traffic is substantially diverted to the Eastern and Western Harbour Crossings, congestion in the vicinity of the Cross-Harbour Tunnel during peak hours may be partially shifted to other areas.

"The consultants will analyse what would be the reasonable toll levels of the road harbour crossings, how to enhance the Government's capability in adjusting tolls of the three road harbour crossings, the cost and benefit of such measures, and will make recommendations on these issues to the Government.

"The Government will keep an open mind in considering various options that would enable the Government to implement more reasonable toll levels, including buy-back and franchise extension."

When it receives the report, the Government will consider the findings and feasibility of the recommendations. It will share with the public the consultant's advice, its own considerations, and listen to people's views.