Commuters who travel by bus are effectively subsidising loss-making routes by paying a high premium when they cross the harbour - an irregularity largely due to the government's fare-mechanism policy that adds up to hundreds of millions of dollars a year.
Based on a South China Morning Post study, the fare per kilometre for a non-tunnel route ranges from 27 cents to 53 cents, while fares for routes using the Shing Mun, Tate's Cairn, Lion Rock and Tai Lam tunnels in the New Territories vary from 21 cents to 42 cents.
By contrast, the fare per kilometre for cross-harbour bus routes is between 41 and 77 cents.
The irregularity is much more acute for short-distance, cross-harbour trips. For example, the 3km bus ride between Hunghom and Causeway Bay through the Cross-Harbour Tunnel costs $8.90 - or $2.97 per kilometre.
Cross-harbour tunnel operators charge buses between $5 and $70 each per crossing. So if a double-decker is half full with 55 passengers, the cost of taking each person through a tunnel should be between nine cents and $1.27.
A 22.6km bus ride from Tsuen Wan Ferry Pier to Laguna City in Lam Tin, which does not pass through a tunnel, costs $7.30. By contrast, a trip of similar distance between Siu Sai Wan and Wong Tai Sin, via the Cross Harbour Tunnel, costs $9.40.
