The government said on Friday that it plans to change laws to mandate all electric cars to install a vehicle alert system – because they're too quiet when they're driven slowly.

In papers submitted to the Legislative Council, the Transport and Logistics Bureau pointed out that pedestrians may not be aware of these vehicles when they’re going at less than 20km/hour, and overseas studies have found that quieter cars have a higher chance of hitting people.

Transport officials said since July last year, newly-registered electric vehicles are already required to install an acoustic vehicle alert system which would emit sounds of up to 75 decibels.

To further enhance road safety, they said the plan is to expand the requirement to older electric cars and mandate their owners to install the system within a year of the enactment of the amended legislation.

Under the government proposal, car owners who violate the rule could be liable to six months in jail and face a maximum fine of HK$10,000.

Authorities said they plan to submit the proposed changes to Legco in the first half of next year.