The government said on Monday it's postponing the launch of a new tunnel toll system until May, to give people more time to adopt the new scheme.

The "HKeToll" was meant to be rolled out at the Tsing Sha Control Area on February 26 to replace manual toll booths and autotoll lanes for the Eagle's Nest Tunnel, but that's now been pushed back to May 7.

The scheme involves the logging of journeys through a tag attached to vehicle windscreens, or via number plate recognition technology. Fees will be deducted automatically from the tag users bank account, or a bill sent to the vehicle's owner for payment.

Transport commissioner Rosanna Law said officials decided to postpone "HKeToll" after getting complaints from drivers, especially taxi groups.

"We hope everyone can have more time to understand the application procedures, to apply for the vehicle tags, and link your accounts to the tags," Law told reporters.

"The concerned industries can also know more about how this operates, and we can add over 20 service stations to help people with their application and account linkage."

She said details about the service stations will be announced later.

Law stressed that the plan is still to implement the new payment system and phase out toll booths at all government tunnels by the end of this year.

She stressed that drivers who don't want to get a tag can still use tunnels where the new toll system is in use. She said they would only need to pay the toll within 14 days of receiving a payment demand.

The Transport Department said that it had issued some 430,000 tags so far, and it will send out a letter to all 800,000 car owners in Hong Kong on Friday to remind them of their electronic contact details with the department.

The government announced the delay after a commercial drivers' union staged a demonstration at the West Kowloon Government Offices, in Mong Kok, accusing the authorities of ignoring the digital gap faced by some older drivers.

The Motor Transport Workers General Union also called on the government to improve promotion of the "HKeToll" scheme, so that passengers, especially tourists, won't mistakenly believe that trips through tunnels are free just because drivers don't have to stop at toll booths.