A reminder for anyone who drives with kids in their car -- New York's new car seat law went into effect Friday.

All children under the age of 2 must now use a rear-facing car seat.

Studies show rear-facing seats are the best option for a young child because they are equipped with a harness and, in a crash, cradle and move with the child to reduce the stress to the child's neck and spine.

Dr. D'andrea Joseph, of NYU Winthrop Hospital, says the law could save lives.

"The back-and-forth motion that occurs when you have an impact is more easily tolerated when you're in a rear-facing seat," Joseph says. "You don't have as much motion."

If your child outgrows their infant seat before the age of 2, experts recommend an all-in-one seat with higher rear-facing height and weight limits.

Car crashes are a leading cause of death for children ages 1 to 13, according to the state Traffic Safety Committee.

AAA lobbied for the law and says it's important for parents to make sure the seat is properly installed.

Experts say all car seats are different and some are not capable of rear-facing.

"If the child is in a convertible seat, it's designed to go back rear-facing and forward-facing," says Shani Jarvis, certified child seat safety technician. "So if it's a convertible seat, they do not need to go into, you don't need new equipment or a new seat. If it's an infant-only seat, then you would need to upgrade to a convertible seat."

Experts recommend keeping children rear-facing as long as possible.

At least six other states have a similar law.