The transport chief has defended a plan to charge motorists HK$10 for using the Central Kowloon Route after several lawmakers called on the government to consider adjusting the across-the-board fee.

Secretary for Transport and Logistics Mable Chan on Friday said the authorities are trying to strike a balance between striving to recover costs and ensuring public usage in coming up with a suitable toll level.

The administration had considered various options for the route, including toll-free access as well as fees of HK$10 or HK$17.

A Yau Ma Tei section is expected to open this year.

A number of lawmakers complained that the proposed fee level was too high, with one of them, Chau Siu-chung, raising the possibility of halving the charge to HK$5.

Fellow legislator Bill Tang urged the government not to rush into charging motorists but to instead let them use the route for free initially.

"How about we wait until it opens at the end of this year and monitor actual traffic flow before deciding on the toll?" he said.

"And if the government is setting a fee level, depending on whether the community accepts it, how does HK$8 sound?"

Chan said a cheaper toll fee might not be the best option.

"We need to spare some capacity when the traffic load increases," she said.

"We need to be prepared.

"In terms of diverting traffic and capacity, charging HK$8 is definitely not as ideal as a HK$10 fee... But of course, it's most important that residents will use the route.

"Otherwise, it's not worth it to simply charge tolls to the point where residents will not use the route."

If lawmakers approve the proposal, the government plans to charge road users in the middle of next year, when the entire bypass is scheduled to be completed.

Officials also plan to raise tolls at Aberdeen and Shing Mun tunnels from HK$5 to HK$8, citing the fact that the fees have not been increased in 34 years.

The new charges for the two existing tunnels could take effect within a month upon approval by the legislature.

Separately, the government said time-varying tolls implemented in late 2023 at the city's three harbour crossings would remain unchanged for now amid further monitoring of the situation.

Since the tolls shake-up at the tunnels, traffic flows at Western Harbour Crossing have increased by 19 percent to around 104,000 vehicles per day, according to official figures.

To handle the increased traffic load, transport authorities plan to construct an additional lane at the tunnel's exit on the Hong Kong Island side. The work is to be completed by the first quarter of 2026.