The new car seat safety law requires that children under the age of two must be placed in rear-facing car seats unless the child meets or exceeds weight and height guidelines. Maryland would be joining 16 other states, including Virginia and D.C., in requiring this safety measure.

The shift comes after reports that nearly half of all car seats are installed incorrectly, according to The National Highway Traffic Safety Administration (NHTSA). The NHTSA recommends keeping children in a rear-facing seat from birth to three years, or as long as possible until they reach the height and weight limit allowed by the car seat’s manufacturer. The logic is that rear-facing car seats prevent the child’s head from snapping forward, protecting the vertebrae and the neck in a crash. Children under two years old are 75% less likely to die or sustain serious injury in a rear-facing seat, according to a 1988-2003 crash database from the NHTSA.

The law takes effect Saturday, Oct. 1. Violators may be subjected to a written warning for their first offense but will be fined afterward.