On Monday, a new traffic law will force Londoners to buckle up their children or face stiff penalties. From September 18, all children under four foot five inches (about 135 cm) must be secured in a car seat or booster seat. Those who ignore this rule will face a mandatory traffic fine of £30 to £500 (if referred to court.) Although many parents strap their children in, many do so incorrectly and allow the children to use adult seat belts before they are big enough to do so. Air bags can also cause serious injury to children who are strapped into car seats in the front passenger seat. “Most people make sure that children use some kind of restraint when travelling on the road, but it is vitally important to use the right one; and not to use an adult belt before the child is big enough,” said Transport Minister Stephen Ladyman. The move aims to reduce the high number of serious injuries and deaths caused by improper restraints each year.