With all the concern most parents express about the safety of their children, it is surprising -- no, shocking -- that so many parents are so casual about a proven safety measure that could make a life-or-death difference: the consistent use of proper child restraints in motor vehicles, especially for children who are too old for infant and child safety seats and too young for adult seat belts.
In New York State, parents cannot take a newborn home from the hospital in a car without a proper car safety seat.
Further, all states have laws that require children under the age of 4 to be restrained while they ride in cars, and 25 states require that children up to 16 be restrained at all times.
And, after a series of deaths caused by air bags, parents have been advised to place all children 12 and under in the rear seat, where the risk of death in an accident is 35 percent lower than it is among front-seat occupants.
Yet despite all the laws and warnings, motor vehicle accidents remain the single largest cause of death among children 15 and younger.
Children at Risk
Analyses of fatal accidents have shown that there are many a slip between the law and the proper use of restraint systems, especially once children outgrow their child safety seats.
Furthermore, there are many gaps in the laws for children aged 4 through 8. In 19 states, children in this age group can ride unrestrained in the back seat of a motor vehicle.
And no state requires the use of booster seats for children who have outgrown their car seats, even though booster seats, which raise youngsters high enough so that the adult lap-and-shoulder belt can be used safely, is the only proper way to protect children in this age group.
''After age 3, child safety seats are pretty much out of the picture,'' said Dr. James Nichols, director of research and traffic records at the National Highway Traffic Safety Administration. ''Children are either not restrained at all or they are put -- improperly -- in adult seat belts.''
To make matters worse, many youngsters are allowed to ride in the front seat, where the impact from an air bag can kill them if a crash doesn't.
The safety agency has just begun a $7.5 million nationwide campaign, ''Don't Skip a Step,'' to alert parents to the urgency of using booster seats for children weighing 40 to 80 pounds.
Although there has been a decline in crash-related deaths among infants thanks to greatly increased use of infant safety seats (which should always be placed in the back seat facing the rear of the vehicle), fatalities among children ages 4 to 8 have remained stable since the mid-90's.
In a new study of fatal crashes conducted by the National Center for Injury Prevention and Control, from 1994 through 1998, there was little change in the death rate, the use of restraints or the seating position among children in the 4 to 8 age group who were killed in crashes.
The study, by Steve Trockman and Dr. Ann Dellinger of the Centers for Disease Control and Prevention in Atlanta, found that the death rate, adjusted for age, remained about 2.6 per 100,000.
Of those killed, only 35.2 percent were using some kind of restraint in 1994, a figure that climbed minimally to 38.1 percent in 1998.
The proportion of children killed while sitting in the back seat was 50.1 percent in 1994 and 53.7 percent in 1998.
During the study period, 14,411 children ages 4 through 8 were involved in vehicle crashes in which one or more fatal injuries occurred.
Of these, 2,549 -- 17.7 percent -- died. In other words, each year motor vehicle accidents took the lives of about 500 children in this age group, at least half of whom would have survived had they been properly restrained when the crash occurred.
The National Highway Traffic Safety Administration cites even more frightening data.
In 1998, the latest year for which statistics are available, only 4 percent of 5-year-olds who were involved in fatal crashes were in any form of child restraint, and of those children who died in the crashes, fewer than 2 percent were in appropriate safety seats at the time.
Of 609 5-year-olds involved in fatal crashes that year, 211 had no restraint at all and 262 were using some sort of seat belt, which is an inappropriate restraint for their size and can result in serious injury.
''In our observational studies, seldom do we find more than 6 or 7 percent of 5-to-8-year-olds in a booster seat,'' Dr. Nichols said. ''It's always less than 10 percent of the children who are in a seat that is appropriate for them.''
Yet when parents are surveyed, Dr. Nichols said, most feel that they already know all that they should know about keeping their children safe in motor vehicles. ''Almost no one wants to know anything more about child safety seats, and specifically about booster seats,'' he said.
Protecting Children Properly
The American Academy of Pediatrics recommends the following guidelines. From birth and until children weigh at least 20 pounds and reach 1 year of age, they should ride in an infant car safety seat facing the rear of a vehicle.
This reduces the risk of spinal injury in case of a crash and avoids the risk of injury from an inflating air bag.
Infants who reach 20 pounds before age 1 should still ride facing the rear in either a convertible safety seat or in an infant seat approved for the higher weights.
Children older than 1 who weigh 20 to 40 pounds can ride in a child safety seat facing forward, as long as it is still in the back seat.
Once a child is too big for a child safety seat but still too small to use an adult safety belt, a belt-positioning booster seat should be used. This allows the shoulder harness of the vehicle's safety belt to cross the child's chest and the lap belt to fit across the upper thighs.
If a shoulder strap rides too high on the child, he could be strangled during an accident. And if the lap belt crosses the abdomen, serious internal injury could result upon impact.
Dr. Nichols notes that many booster seats come with their own harnesses, which should be used to restrain the children until they are big enough for shoulder-and-lap belts to be positioned properly. Of course, the booster seat itself must be secured by a lap belt in the rear of the car.
The pediatric academy strongly advises against the use of add-on devices (not those that are built into the vehicle) that try to reposition the shoulder portion of the safety belt so that it fits correctly on passengers who are short.
The best way to get children always to use proper vehicle restraints is for their parents to buckle up themselves and for parents to insist that the children be properly restrained before turning on the engine. And though many youngsters may clamor to sit in the front, the academy insists that the back seat is ''the safest place for children of any age to ride.''