Washington Post
After the other driver ran a red light and plowed into her minivan, Christine Miller of Santa Clarita, Calif., looked in the back seat for her son Kyle, but he had been thrown from the vehicle and was gone forever.“If the scars on my heart were visible, people would gasp every time they saw me,” says Miller. Three-year-old Kyle was sitting in a legal booster seat and strapped in by a seat belt at the time of the collision. “Had I just known about the dangers of booster seats for toddlers, had somebody warned me, I would have kept him in a five-point harness car seat,” says Miller. “That’s the dagger that twists in my heart.” She’s not alone. Car accidents are the No. 1 killer of children ages 0 to 19 in the United States, according to the Centers for Disease Control and PreventionSafe Kids Worldwide says car seats can reduce the risk of death by as much as 71 percent, but they have to be installed and used correctly. More than half of them aren’t.
“We find parents often make several mistakes at the same time,” says Lorrie Walker, training manager for the Safe Kids Buckle Up program. “Taking just a few minutes to make sure your car seat is installed and used correctly could be the first step to saving a life.” Here are the top mistakes parents make, and how to avoid them and keep your child safer while on the road.
Mistake 1: ‘Promoting’ your child too soon
We parents seem to want to keep our kids young — except when it comes to their car seats. That’s misguided. In addition to delaying things such as violent video games and makeup, we should delay kids’ progression through the stages of car seats. They should stay in each position and seat as long as they safely can. Each step up is actually a bit more dangerous because it offers less protection for growing bodies.
Rear-facing seat: 
The American Academy of Pediatrics recommends that all children ride in a rear-facing car seat until they are at least 2 years old or reach the weight and height limits set by the seat manufacturer. The National Highway Traffic Safety Administration agrees. Research has shown that rear-facing seats distribute the force of a crash over a large area of a baby or toddler’s body, keeping them safer. Look for an infant seat with higher height and weight limits so you can keep your child in it longer. Better yet, Consumer Reports says transitioning to a convertible seat, but keeping it rear-facing, has additional head-protection benefits.
Forward-facing seat with five-point harness: 
These seats also attach to your vehicle. NHTSA says to keep your child in this type of seat “until he or she reaches the top height or weight limit allowed by your car seat’s manufacturer.” The challenge is that those limits vary widely — from about 48 to 58 inches in height and 50 to 90 pounds in weight. In fact, if you look at NHTSA’s car seat finder tool, you have a choice of either a 5-point harness seat or a booster seat for two entire years, between ages 4 and 6. This is the problem Miller ran into. Her son Kyle was heavy enough to age out of the forward-facing seat they owned, so they moved him to a booster. A five-point harness seat might have saved him. Manufacturers now offer larger five-point harness seats that accommodate older kids. And if your child resists, point out that NASCAR drivers also use five-point harnesses.
Booster seat: 
You shouldn’t skip this step. Booster seats are designed to raise children to a height where they can safely wear the vehicle’s built-in seat belt. Consumer Reports says high-backed boosters are safer than backless ones because they do a better job of properly positioning the seat belt across the child’s chest, hips and thighs. The Centers for Disease Control and Prevention says booster seats can reduce a child’s risk of serious injury by 45 percent.
Mistake 2: Obeying state law instead of federal recommendations
State laws are made by politicians who aren’t crash engineers and are often behind the curve on current safety standards. Think of your state law as the minimum you should do — not the maximum. Go by the federal recommendations from the experts at NHTSA or the Academy of Pediatrics instead.
Seat belt only: 
Most states require your child to ride in a booster seat only until age 8. But according to Janette Fennell, founder and president of the safety group KidsAndCars, moving a child from a booster seat to just a seat belt is “the most significant safety demotion.” So use this five-point test to determine whether your child is ready to use just the seat belt: 1. Their back is flat against the seat back. 2. Knees bend over the edge of the seat and feet are flat on the floor. 3. The shoulder belt sits on their shoulder and chest (not face or neck.) 4. The lap belt sits low on their hips and touches their upper thighs (not on their stomach.) 5. Your child can sit comfortably this way for the entire trip.
Front seat:
Most state laws don’t specify that children should sit in the back seat, but the AAP says children should stay in the back seat until their 13th birthday. Many children were killed by air bags before parents were advised to have their children sit in the back, because the child was too small to absorb the force of the inflating air bag, according to NHTSA.
Mistake 3: Not reading the manuals
Yes, that’s manuals — plural. You need to read both the car seat manual and your car’s manual. It may sound like a hassle to absorb every page, but it’s crucial. Safe Kids did a study that showed 64 percent of parents aren’t using the top tether that keeps a car seat from pitching forward. Failure to use it can result in serious head injuries. The seat manual will tell you where to find the top tether, and your car’s manual will tell you where to attach it.
Mistake 4: Passing up free help
Installing a car seat correctly is not easy. Certified experts train for as much as 40 hours, so seek out those pros and get their help. It’s usually free. Both NHTSA and Safe Kids provide lists of local car seat checkups, where experts can spot the critical mistakes that get kids killed, like if your car seat or its straps are too loose, or if your straps or chest clip are positioned at the wrong height.
Mistake 5: Not considering the seat’s history
Safety advocates suggest not accepting a hand-me-down car seat, because you don’t know whether it’s been through an accident and it may not incorporate the latest technology. Some suggest you avoid rental car company car seats for the same reasons. If your car seat is in an accident, replace it. Car insurance often covers the cost. Finally, car seats have expiration dates. Make sure to buy a new one that isn’t near the expiration date, and get rid of old ones that are past it.