Arbitrators have rejected a toll increase of about 40 per cent for the Eastern Harbour Tunnel, with charges likely to remain unchanged for at least four years.
The government welcomed the decision and the undersecretary for transport and housing, Yau Shing-mu, said: "The public will not need to suffer the consequences of a toll increase."
Operator New Hong Kong Tunnel took the matter to arbitration after the Executive Council in June last year rejected its application to raise tolls by between 38.5 per cent and 42.1 per cent.
The company's 30-year franchise ends in 2016, and the chances of it applying for another toll rise before then are slim.
Despite the arbitrators' decision, the company said it would continue to "provide a safe and high-quality tunnel service". It had argued the rise was needed to keep its operation profitable.
The company continues to pay the construction and on-going maintenance expenses for the 2.2-kilometre tunnel, which will be transferred back to the government in 2016.
Richard Tsoi Yiu-cheong, of the Coalition to Monitor Public Transport and Utilities, believes that after 2016 the tunnel will be managed like the Cross-Harbour Tunnel linking Hung Hom and Causeway Bay. The government would own the tunnel and have final say on toll levels and other management issues, he said.
Although the government could then divert traffic by adjusting the tolls of the two tunnels, Tsoi said congestion could not be ideally alleviated until the Western Harbour Crossing's contract ended in 2023.