New legislation requiring public light bus passengers to wear seat belt will come into effect next month, the Transport Department says.

From August 1, public light bus passengers must wear seat belts if they are installed on their seats. Registered public light buses will be required to be fitted with seat belts and high-back seats.

Announcing details at a briefing, the Transport Department's Senior Engineer for Road Safety Edmond Fok said it is the passenger's responsibility to ensure that he or she wears a seat belt on a public light bus.

"Any passenger who is found not wearing a seat belt when it is provided will be subject to a maximum fine of $5,000 and three months' imprisonment," he said.

"Drivers are encouraged to remind the passengers to wear a seat belt and they may refuse to drive if a passenger refuses to do so," he added.

Each seat belt must be used by one person at a time. If three children aged three years or over, who are less than 1.3 metres tall and counted as two adults take the bus, the extra child will not need to wear a seat belt since it will not be available.

Pregnant women can apply for exemption

A pregnant woman is also required to wear a seat belt. A valid medical certificate is required to apply to the department for an exemption.