When my oldest son was 9, I took him to the pediatrician's office for his annual wellness exam. I'm pretty sure he hadn't been using a booster seat in the car for some time, because I remember my shock when he stood up against the wall to see how he measured up to a piece of tape stuck to it. Any kid shorter than that piece of tape should remain in a booster, the doctors advised.

Did my kid's head touch the line? Nope. Not even close.

Whoops.

For many years, many parents in Minnesota didn't have the most up-to-date rules on when to move their kids from rear- to forward-facing car seats, how long they should remain in a booster, and when it's OK for them to ride in the front seat. This Thursday in Minnesota, that changes.

A new state law prescribes much more detail on how to keep our most important cargo safe. It follows the latest guidance from the American Academy of Pediatricsand is intended to prevent kids from moving onto a less protective level of restraint before they're ready.

The old law mostly steered parents to the manufacturer's recommendations for their car seat for guidance. The new law still takes those manuals into account, but also addresses the child's size and age and even how your child restraint system fits with your vehicle.

"Anybody who's a parent knows that all kids develop differently," said Mike Hanson, director of Minnesota's Office of Traffic Safety. "They grow differently, they have different ages, and they have growth spurts. So we have to look at the child — their age and their size."'

Booster seats until 9

One of the biggest changes in the law? Your kid will need to stay in a booster until age 9, unless they've already outgrown it. (The old rule allowed them to go booster-less on their eighth birthday or when they reached 4 feet 9.) They also need to show they can pass what's known as the five-step test. (I'll get to that in a minute.)

The reason to prolong booster use, as my pediatrician explained to me that day, is that the seatbelt will only work if it fits the body of the occupant. For example, the lap belt must go across the hip bones near the top of the thighs, rather than across the child's belly. That's to prevent injury to internal organs in the event of a crash.

Kids under 13 stay in the back seat

Another notable change in the law is that your preteen won't get to ride in the front. Airbags are designed to protect full-sized adults, not children. Deployment of airbags are "violent" occurrences and can injure a child, Hanson says.

But the statute says anyone under 13 should sit, properly restrained, in the rear seat "when available."

So is this a recommendation or a law?

"This is very clearly a law," Hanson says. "The language in there is legal, statutory language that transporters of kids must follow."

As frequent transporters of kids, though, many of us also carpool. Just this week my 11-year-old jumped at the chance to ride shotgun in my RAV4 while I Ubered him and three of his friends to skateboarding camp.

Hanson acknowledges there will be occasions when the back seat is not available. (Not all of us have the luxury of a third row of seats in our vehicles.) Policymakers inserted language in the law intended to give parents and other drivers some flexibility to decide how to most safely shuttle kids, he said.

New rules for car seats

For babies and very young children, here's what you need to know.

• Kids from birth to at least 2 years old should be rear-facing in an infant or convertible child safety seat.

• If your child is at least 2 and has outgrown the rear-facing seat with harness by height or weight, put them in a forward-facing car seat with an internal harness. (Check your seat's instruction manual for height and weight limits.)

• Any child 4 or over who has outgrown the forward-facing seat with harness by height or weight should ride in a booster seat using the vehicle's lap belt and shoulder belt.

• If your kid falls into more than one category, choose the restraint that is more protective.

Will violators be ticketed?

Hanson said he expects strong compliance once people learn about the changes.

Law enforcement officers have told him that what they've traditionally observed on the road is usually "all or nothing": Either kids are properly restrained in their seats, or they're free-roaming in the car.

"If a peace officer sees one of those free-roaming children, there's probably going to be a stop and some type of enforcement action taken," he said. "Officers are going to try and educate to the best of their ability, but if there's a clear violation, they will take action."

Five-step test

Kids can ride without a booster if they pass the five-step test showing they can properly wear a seatbelt: The child sits all the way back against the vehicle seat; their knees bend over the edge of the vehicle seat; the seatbelt's lap strap fits snugly across the child's thighs and lower hips (not the child's abdomen); the shoulder strap snugly crosses the center of the child's chest (not the child's neck); and the child sits correctly, without slouching, for the duration of the ride.

If you have more than one vehicle in your family, you should do the test in each setting. It's possible your kid might meet the five steps in your Hyundai Elantra but not in, say, your four-door Ram pickup.

My takeaways

According to a five-year stretch that ended in 2023, nearly 13,000 kids up to 7 years old were involved in Minnesota car crashes and were properly restrained. Here's a beautiful statistic: 89% were not injured, and an additional 10% had only minor injuries.

If you're unsure how to properly secure your child in the car, schedule a car seat check with a certified technician by heading to bit.ly/MNcarseatchecks. Check out buckleupkids.dps.mn.gov for more resources.

With this rollout of changes, there might be some confusion and possibly a few complaints from kids who might think sitting in a booster is for babies, or that riding shotgun before you're 13 is cool. But the new law offers some much-needed clarity and just enough flexibility.

It just may take some time for us caregivers to catch on.