Children in cars—keeping them safe at every age

By Mary Pat McKay, MD, MPH, and Liesl Curtis, MD

Counseling about car safety shouldn't hit the brakes when a child graduates from an infant seat or booster seat. Here is what parents need to know to help children ride safely from birth through adolescence.

It is that simple: Traveling in a motor vehicle is the most dangerous thing children do, causing more death and disability than any other activity. Motor vehicle crashes are the number one cause of death among children at every age after their first birthday. In 2001, 4,593 American children 18 years of age and under died as a result of riding in a car,¹ and more than 610,000 were injured.² The majority of deaths and serious injuries are readily preventable.

Pediatricians play a pivotal role in guiding parents through the growth and development of their children, providing advice on everything from teething to toilet training. Although pediatricians often discuss child passenger safety with the parents of their youngest patients, the subject comes up less often as children age.³ Moreover, some evidence suggests that physicians are poorly trained to give specific advice on the safest ways for children to ride in cars.⁴ Yet parents are interested in receiving more advice from pediatricians⁵—and the correct advice could easily save a child's life.

What is the safest way for children to travel in the car? How do safety recommendations change as children grow? How important are booster seats? When is it safe for a child to ride in the front seat? What guidance should the pediatrician be giving when teenagers begin learning to drive? This article addresses these and other passenger safety issues.

Birth to 1 year: Rear-facing infant safety seats

Keeping abreast of all the permutations of infant safety restraints and devices is virtually impossible, even for the most committed pediatrician. However, knowing the basics is crucial. Giving a parent misinformation about the safest way to transport a child could result in significant injury. The first tenets of child passenger safety are that all children need to be properly restrained while riding in a vehicle and that this requirement begins at birth.

Because of their relatively large head size and weak necks, healthy young infants (over five pounds) should ride in a rear-facing child safety seat. Facing backward allows the distribution of deceleration forces over the infant's entire trunk in a crash, subjecting the spine to less extreme flexion and resulting in fewer fractures, dislocations, and deaths.⁶ It is a misconception, however, that when an infant can sit up and support his own head he is ready to sit forward-facing in the car. Rear-facing is recommended because of the incomplete ossification of infants' vertebrae and their lax connecting ligaments, not because of weak neck musculature.⁷ The American Academy of Pediatrics (AAP) recommends, therefore, that infants ride facing backwards until they are both 1 year of age and weigh more than 20 pounds.⁸

The proper position for the rear-facing infant is semi-reclined at an angle of approximately 45°. This position helps support the infant's head to prevent slumping and airway obstruction. Two kinds of seats can be used: infant-only seats, designed to face rearward exclusively, and convertible seats that can be turned in either direction. Many infant seats come with a separate base, which makes carrying the baby in the seat and reinstalling it in the car easier. It may be necessary to place a bolster (such as styrofoam "noodles" that are used in swimming pools) between the base of the safety seat and the cushion of the car's seat to achieve the proper angle; convertible seats often have kickstands. Many have a level indicator that indicates proper positioning.

The upper limit of a child's weight for an infant seat is often 20 pounds, so a convertible seat must be used when the child approaches 20 pounds but is not yet 12 months old. Parents of children who weigh more than 12 pounds at the 4-month check-up should be counseled to consider switching to a rear-facing convertible seat. It is important to review weight limits on all safety seats; each has been tested to some maximum weight.

Although installing the safety seat properly in the vehicle may be difficult, assessing the installation should be easy. The seat should be tightly bound to the vehicle seat with no more than one inch of play in both the front-to-back and side-to-side positions when the safety seat is pushed or pulled forcefully. Because seat belts have "give" to allow normal motion and only lock up in the event of a crash, the belt holding the safety seat in place must be locked into position. Depending on the vehicle, a locking mechanism may be built into the clip itself. If not, an extra "locking clip" may be needed to keep the vehicle's safety belt tight (Figure 1). Locking clips typically come with the safety seat but also can be purchased separately. To avoid head injury, the handles and canopies on infant seats need to be in the down position during travel.

The National Highway Traffic Safety Administration (NHTSA) has responded to the difficulty of installing child safety seats by formulating new regulations that require all passenger vehicles after model year 2002 to be equipped with tethering systems (Lower Anchors and Tethers for Children, or LATCH) that make installation of car seats much easier.⁹ This increasingly available technology allows the car seat to be slid into place with two clicks, one for the bottom anchors and one for the tether. New child safety seats come equipped with tethers.⁶ When in doubt about car seat installation, your best choice is to send the family to a "car seat technician," someone formally trained by the NHTSA to install safety seats and perform safety checks. Car seat technicians are available across the United States. (For more information on car seat installation and availability of local car seat safety checks, go to www.nhtsa.dot.gov/people/injury/childps/CPSFitting/Index.cfm .)

The infant must be securely strapped into the child safety seat. The straps should fit snugly so that the gap between the strap and the child's clavicle is no greater than one finger width. The plastic chest clip should be at the level of the child's armpit, where it helps to keep the shoulder straps in place. In a crash, loose straps or low chest connectors can lead to ejection if the infant's sloping shoulders slip out of the straps. The straps should be free of twists and positioned in the lower slots of the car seat for the rear-facing position (Figure 2).

Although all 50 states mandate safety seats for infants and their use has become fairly routine, misuse is all too common. The NHTSA funds an observational study to evaluate restraint use—the National Occupant Protection Use Survey (NOPUS)—which recently showed that 99% of infants under 1 year of age ride in a safety seat. Unfortunately, 15% of the infants were placed in the front seat, and only 32% were properly positioned facing rearward.¹⁰ Of the 100 infants under 12 months of age who were fatally injured while riding in a motor vehicle in 2001, 29 were in the front seat and only 42 were riding in a car seat.¹¹ These findings call attention to the need for more parent education about using infant seats.

It is worth noting that safety seat use is much lower (as low as 19%) among low-income and minority populations than other groups in the US.¹² Parents in these populations may require additional motivation from the pediatrician to use a safety seat. The reasons for low safety seat use are complex and may be specific to the family or cultural community. A common thread, however, appears to be the belief that the need for the infant to bond with caregivers is more important than keeping the baby in a safety seat when traveling. In addition, parents may get conflicting advice from advisors who mistakenly believe infants are safest when carried in a mother's arms, even in the car. Pediatricians can play a role in overcoming these concerns by reassuring parents that bonding can occur at other times than while riding in the car and that the safest way to calm a crying child while traveling is to park the vehicle before removing the infant from a safety seat. It may also help to remind parents of a basic principle of physics: In a crash at only 30 miles an hour, a 10-pound infant becomes a 300-pound force straining to escape the caregiver's arms (force = mass x acceleration). No one can reasonably expect to keep such a projectile contained.

For parents who do not have a safety seat, money is the primary issue 70% of the time.¹ Safety seats can cost more than $100, and children need a series of new seats as they grow. Pediatricians need to ask parents if cost is the problem and know what alternatives to buying a seat are available within the community. Local hospitals may have giveaway or lending programs for infant seats; car care retailers may make available lower-cost car seats of all sizes; or the local Safe Kids Coalition ( http://www.safekids.org/ ) may have or know of low-cost or rental options.

In vehicles with a front passenger airbag, the infant seat must be placed in the back seat of the vehicle because the rear-facing position of the safety seat places the infant's head directly in the path of a deploying airbag (Figure 3). As of January 1, 2003, 22 infants had died as a direct result of deployment of the front passenger airbag. All were sitting in rear-facing safety seats in the front passenger position and all were killed in crashes that, experience shows, would otherwise have been survivable.¹³ Vehicles that do not have a full-size rear seat are now equipped with a turn-off switch for the front passenger airbag, which must be in the OFF position when an infant is riding in the front seat. Families with several children who need to place a child in the front seat should choose the oldest child. If that child is younger than 12 years, the parents can have an airbag turn-off switch installed. (For more information on turn-off switches for air bags, see http://www.nhtsa.dot.gov/airbags/ .) [Editor's note: For a discussion of front airbags and children, see "Airbags and children: A mixed blessing" in the April 2001 issue.]

Side airbags are a new phenomenon and are not regulated by the NHTSA. They can be placed in either the front or the rear seat and deploy out of the roof rail, the side of the seat, the window rail, or the armrest. Children seated close to a side airbag may be at risk of serious or fatal injury¹⁴; this may be particularly true for infants in seats that are very close to or touching the side door. The NHTSA has asked automobile manufacturers to ship vehicles with the side airbags deactivated. The purchaser can ask to have them activated after they have been advised of the potential risk to children seated near them. Parents should discuss with the dealer the type and position of side airbags before purchasing a new car.

1 year to 4 years: Forward-facing child safety seats

Once a child is 1 year old and weighs more than 20 pounds, she may be placed in a forward-facing safety seat. Toddlers are still safer facing backward, so there is no need to make the switch until the child has reached the maximum weight for the rear-facing seat. Convertible seats can be turned around and reinstalled. (Some safety seats are designed and tested to be forward facing only.) Because each seat is tested for certain weight limits, it is important to check the manufacturer's information booklet to ensure that the toddler and the seat are a match. Forward-facing seats are installed in the upright position and should pass the same secure fit test as infant seats (no more than one inch of play in any direction). Some vehicles have integrated car seats. They are typically suitable for toddlers, but weight limits vary by maker; details should be available in the vehicle owner's manual.

When a child is facing forward, the harness straps must be placed through one of the upper sets of slots so that they come over the top of the child's shoulders. Straps in these slots not only serve to hold the child in position, but also spread crash forces over the part of the seat that is engineered to withstand them—the reinforced portion of the back of the seat. The chest clip should be connected to both straps on every trip and sit at about the level of the child's armpits. Just as with an infant seat, the harness straps must be snug. The parent should be able to slide no more than two fingers between the straps and the child.

Toddlers should remain in a safety seat until they reach at least 40 pounds. However, they can stay in this type of seat as long as it fits well: The top of the child's ears should be below the top of the back of the safety seat, the shoulders should be below the uppermost strap slots, and the child's weight should be below the maximum manufacturer's recommendation.

The same issues with airbags exist for toddlers as for infants. Toddlers, like infants, should not ride in the front when the vehicle has a functioning front passenger airbag. A recent study by the NHTSA found a high rate of misuse of turn-off switches for these airbags. The switch was left on inappropriately in 25% of cases involving passengers 1 or 2 years of age, and the misuse rate increased with increasing age. Moreover, the switch was off 18% of the time when an adult was in the passenger seat.¹⁵ Although there is little hard evidence, toddlers may be at risk of injury from side-impact airbags, and the switches for these airbags should probably be turned off.

Laws in all 50 states mandate the use of safety seats for children to 4 years of age. This does not, however, mean the seats actually are used or that they are used properly. The NOPUS study mentioned found that although 94% of 1- to 3-year-olds were in some child seat, 10% were riding in the front seat and only 62% were using the correct, forward-facing toddler seat.¹⁰ Of the 361 toddlers between 1 and 4 years of age who were killed in a car crash in 2001, 94 (26%) were riding in the front seat and 143 (39.6%) were not restrained at all.¹⁶

An important message to convey to parents about all child safety seats is that, if the seat has been subjected to a crash of any severity, it must be thrown away—even if they think that it "looks OK." The crash has stressed the components of the seat, and plastic and metal parts are not as strong as they were before and will not protect the child optimally in the next crash. This is one reason a used car seat may not provide maximum safety. A second reason is that car seats sometimes get recalled, and unless the parents have registered the seat, they probably will not find out there was a problem until their child is injured. Child safety seats can be registered through the manufacturer or at www.nhtsa.dot.gov/people/injury/childps/csregfrm.pdf so that parents receive notification of problems. Pediatricians need to actively encourage parents to register their child's seat through the manufacturer or online.

5 years to 8 years: Booster seats

Children between 5 years and 8 years of age who weigh more than 40 pounds are too big for toddler seats but not yet large enough to fit the seat belts designed for adult passengers. The lap belt, designed to fit across the strong pelvic bones in an adult, slips up to ride across the mid-abdomen of a child. In the event of a crash, the belt applies maximum force to the unprotected abdominal contents along with excessive forward flexion, resulting in a serious "seat belt injury," such as a duodenal wall hematoma, transected pancreas, or fracture of the posterior elements of the lumbar spine with transection of the spinal cord.¹⁷ In addition, children who are graduated prematurely to a built-in seat belt are at risk of "submarining" (sliding out of the lap belt) and neck injury caused by improper fit of the shoulder belt. Moreover, poor fit makes the shoulder belt uncomfortable, so the child puts it under the arm or behind the back, increasing the risk of injury in a crash.

Many devices are marketed to improve the fit of the adult-sized seat belt for children. They usually attach to the seat belt and all do the same thing: pull down the shoulder harness for comfort at the expense of pulling up the lap belt, dangerously, over the abdomen. The devices have not been crash tested, and they decrease the integrity of the safety system. They should never be recommended to parents.⁸

The best solution in this age group is a booster seat, which simply raises the child a few inches, improving the fit and comfort of the seat belt. Recent research suggests that booster seats lower the risk of serious injury by 59% compared with seat belts alone.² Because booster seats do not have to be secured directly to the seat of the vehicle, they are easy to use. Although all of the booster seats on the market meet Federal Motor Vehicle Safety Standards, the AAP recommends the high-back booster because it provides some head support (Figure 4).⁸ Low-back and no-back boosters do not offer head or neck protection. Booster seats should always be used with a lap and shoulder belt rather than the lap belt alone.

Beginning when a child weighs 40 pounds and outgrows the forward-facing toddler seat, a booster seat should be used until the child reaches 4 feet, 9 inches in height and 80 pounds in weight and can sit with the lap belt low and flat across the thighs and the shoulder belt across the chest (over the midclavicle and center of the chest). The child's bottom must rest against the seat back, and the knees must be comfortably bent over the edge of the seat.

Only seven states mandate the use of booster seats for children.¹⁸ Allowing for the fact that booster seat use is hard to observe because low-back boosters are not visible from outside the vehicle, the NOPUS study found that only 6% of children 4 to 7 years of age were using the recommended high-back booster, only 83% were restrained at all, and 29% were riding in the front seat. For all children from birth to 7 years, the child was much more likely to be restrained if the driver was wearing a seat belt.¹⁰

9 years to 14 years: Back seats and seat belts

For children of any age, riding in the back seat is safer than riding in the front and is associated with a 30% reduction in fatal injury—46% if the car is equipped with front airbags because of the additional danger airbags pose to children in the front seat.¹⁹ This effect holds true even in side-impact crashes.²⁰ For this reason, the NHTSA recommends that all children under 12 years ride in the rear seat.²¹ This does not always occur, however. Of the 233 9- to 11-year-olds who were killed in a car crash in 2001, 80 (34.3%) were riding in the front seat, and fewer than half were wearing a seat belt properly.²²

Standard seat belts reduce the risk of serious or fatal injury by at least 50% in children over 9 years of age. Seat belt use declines, however, as children grow older. In a recent study, fewer than 40% of 7- to 12-year-olds riding in the rear seat were wearing a seat belt. School-age children are more likely to use a seat belt if the driver is belted; in the same study, only 16% of school-age children were belted when the driver was unbelted.²³

Teenagers: Seat belts and supervision

Many new health and safety issues arise as children enter adolescence. Teenagers' willingness to take risks puts them in danger of early pregnancy, sexually transmitted diseases, tobacco addiction, and drug and alcohol problems. But each of these risks directly affects a relatively small percentage of the total teenage population. On the other hand, more than 80% of the US population has learned to drive by 20 years of age.

A driver's license is a badge of independence awarded on the road to adulthood—one greatly anticipated by most teenagers. The novice driver, however, poses a serious health threat to himself or herself and others on the road. With a driver's license, the teenager's activities suddenly change²⁴ and so does the risk of significant injury—as well as the risk of directly causing injury to someone else. The crash rate for teenage drivers is as high as six times that of older drivers and, in crashes involving a teenager, the adolescent driver is at fault more than 80% of the time.²⁵ Although teenagers account for about 7% of licensed drivers in the US, they are involved in 15% of fatal crashes.²⁶ Sixteen-year-old drivers are particularly at risk,²⁷ and are most likely to be the driver at fault.²⁸ Of 795 16-year-olds killed in car crashes in 2001, 436 (54.8%) were driving, and only 181 (41.5%) of the drivers were wearing a seat belt.²⁹

The high crash risk for teenagers results from a combination of immaturity and inexperience. Immaturity is age related and associated with decreased perception of risk, increased willingness to attempt behaviors identified as risky, and greater suggestibility by peers. Inexperience is skills based and associated with less ability than experienced drivers to perceive specific road situations accurately and with poor estimation of safe turning speeds, traffic gaps, and stopping distances.

Because of the high crash rate for teenage drivers, 37 states and the District of Columbia have enacted special procedures for licensing teens: graduated programs to protect novice drivers from high-risk situations while they are learning.³⁰ In these states, the teenager first must pass a written test to obtain a learner's permit, hold the learner's permit for a mandatory period, then pass a driving test to obtain a junior license. The junior license has specific limitations designed to reduce exposure to risk, including restrictions on nighttime driving and the number of passengers. Finally, the teenager obtains a regular license if he or she remains crash free and conviction free for a specified time.

Graduated driver licensing programs decrease the crash rate of novice teenage drivers,^31,32 but parents in every state, whether or not it has a graduated licensing law, can and should insist on safety for their teenagers who are learning to drive—or riding in a vehicle with a novice driver. The first point to emphasize is the necessity of always wearing a seat belt. Teenage passengers riding with an adult driver are belted less often than the driver, but teenagers riding with a teenage driver are belted less than 50% of the time.³³ Only 83 (22.5%) of the 359 16-year-old passengers who were fatally injured in 2001 were wearing a seat belt.¹

Whether or not the state has legislated limits on teenage driving, simple steps, enforced by parents, can help keep novice drivers from crashing. Parents can ensure that novice drivers learn appropriate skills by requiring that they complete a specified number of hours of supervised driving before they take the road test. Some of that time spent in supervised driving should be at night or in bad weather.

For many parents, having a teenage driver in the family means welcome help with chauffeuring younger siblings. Teenagers who drive with younger children must be educated about child passenger safety and the need to use appropriate restraints consistently for young passengers.

Teenagers are especially at risk of serious crashes at night, beginning at about 9 p.m. Once they are allowed to drive unsupervised, a nighttime driving restriction can help protect them for the first year.^31,32,34 This is easily enforced by parents, who control access to car keys.

For novice teenage drivers, transporting passengers significantly increases the risk of a serious or fatal crash. The increase is greatest for the youngest drivers³⁵ and appears to grow further when the passengers are teenagers³⁶ and when three or more passengers are riding in the vehicle.³⁷ As a result, the National Transportation Safety Board now recommends that "young, novice drivers with a provisional [intermediate/junior] license [be restricted] . . . from carrying more than one passenger under the age of 20 . . . for at least six months."³⁸ This restriction is clearly enforceable by parents, who can not only limit the number of passengers their teenager can carry but also can forbid their child to ride with a novice teen driver.

The pediatrician's role in preventing motor-vehicle-related injuries to teenagers is to emphasize that their burgeoning independence requires an adult approach to their own health and well-being. This means wearing a seat belt, whether they are driving or riding. It means accepting that with increased freedoms comes increased responsibility—such as for the safety of passengers. And it means never driving under the influence of alcohol. A brief discussion with the parent(s) and the teen can help both understand the seriousness of their new roles.

Lifesaving advice

Pediatricians have an important role in preventing serious or fatal injuries to children. The first step is understanding the magnitude of the risk. Because riding in a motor vehicle is the most dangerous thing children do, accurate, straightforward, and timely advice, including who needs to be restrained (everybody), which children should face the rear of the vehicle, when it's safe to move up to a booster seat, who should ride in the front seat, and how to help keep teenagers safe on the road, could be lifesaving. (See "Car safety: Take-home points for pediatricians", "Resources on keeping childen safe in motor vehicles", and the parent guide.)

REFERENCES

1. Fatal Automotive Reporting System, Web Based Encyclopedia, www-fars.nhtsa.dot.gov/queryReport.cfm?stateid=0&year=2001 [limited using age 0-18, occupant in passenger area, motor vehicle not bus, motorcycle or commercial truck], accessed 2/24/03

2. National Center for Injury Prevention and Control, Web Based Injury Statistics Query and Reporting System. Webapp.cdc.gov/sasweb/ncipc/nfrates.html, accessed 2/24/03

3. American Academy of Pediatrics: Periodic survey of fellows: Clearing up car seat confusion. American Academy of Pediatrics www.aap.org/research/ps49aexs.htm , accessed 3/1/03

4. McKay MP, Curtis LA: Car safety seats: Do doctors know enough? Am J Emerg Med 2002;20:32

5. Schuster MA, Duan N, Regalado M, et al: Anticipatory guidance: What information do parents receive? What information do they want? Arch Pediatr Adolesc Med 2000; 154:1191

6. Bull MJ, Sheese J: Update for the pediatrician on child passenger safety: Five principles for safer travel. Pediatrics 2000;106(5):1113

7. Weber K: Appropriate use of child car seats. JAMA 1999;282(18):1721

8. American Academy of Pediatrics, Committee on Injury and Poison Prevention: Selecting and using the most appropriate car safety seats for growing children: Guidelines for counseling parents. Pediatrics 2002;109:550

9. National Highway Traffic Safety Administration. LATCH makes child safety seat installation as easy as 1-2-3. www.nhtsa.dot.gov/people/injury/childps/LATCH/DOTLatch123/ , accessed 3/2/03

10. Glassbrenner D: The Use of Child Restraints in 2002. Washington, D.C., United States Department of Transportation, National Highway Traffic Safety Administration, DOT HS 809 555, 2003

11. Fatal Automotive Reporting System, Web Based Encyclopedia, www-fars.nhtsa.dot.gov/queryReport.cfm?stateid=0&year=2001 [limited using age 0-1, occupant in passenger area, motor vehicle not bus, motorcycle, or commercial truck], accessed 2/24/03

12. Istre GR, McCoy MA, Womack KN, et al: Increasing the use of child restraints in motor vehicles in a Hispanic neighborhood. Am J Public Health 2002;92(7):1096

13. National Highway Traffic Safety Administration: Air bag fatalities. www-nrd.nhtsa.dot.gov/pdf/nrd-30/ NCSA/SVC4Q_2002/ABFSISR.pdf , accessed 3/2/03

14. National Highway Traffic Safety Administration: Consumer advisory: Side impact airbags. www.nhtsa.dot.gov/nhtsa/announce/press/1999/ca101499.html , accessed3/1/03

15. National Highway Traffic Safety Administration: Preliminary results of the survey on the use of passenger air bag on-off switches. www.nhtsa.dot.gov/cars/rules/regrev/evaluate/809306/html , accessed 3/2/03

16. Fatal Automotive Reporting System, Web Based Encyclopedia, www-fars.nhtsa.dot.gov/queryReport.cfm?stateid=0&year=2001 [limited using age 1-4, occupant in passenger compartment, vehicle other than bus, commercial truck, or motorcycle] accessed 2/24/03

17. Winston K, Durbin DR: Buckle up! is not enough. Enhancing protection of the restrained child. JAMA 1999; 281(22):2070

18. Insurance Institute for Highway Safety: Child restraint use. www.hwysafety.org/safety%5Ffacts/state%5Flaws/restrain2.htm , accessed 3/2/03

19. Braver ER, Whitfield R, Ferguson SA: Seating position and children's risk of dying in motor vehicle crashes. Inj Prev 1998;4:181

20. Durbin DR, Elliot M, Arbogast KB, et al: The effect of seating position on risk of injury for children in side impact collisions. Annual Proceedings of the Association for the Advancement of Automotive Medicine 2001:61

21. National Highway Traffic Safety Association: Child passenger transportation tips, #2. www.nhtsa.dot.gov/people/injury/childps/newtips/tip2.html , accessed 3/3/03

22. Fatal Automotive Reporting System, Web Based Encyclopedia, www-fars.nhtsa.dot.gov/queryReport.cfm?stateid=0&year=2001 [limited using age 9-11, occupant in passenger area, motor vehicle not bus, truck, or motorcycle] accessed 2/25/03

23. Ferguson SA, Wells JK, Williams AF: Child seating position and restraint use in three states. Inj Prev 2000;6:24

24. Preusser DF, Leaf WA, Ferguson SA, et al: Variations in teenage activities with and without a driver's license. J Health Policy 2000;21:224

25. Ryan GA, Legge M, Rosman D: Age-related changes in drivers' crash risk and crash type. Accid Anal Prev 1998; 30:379

26. National Highway Traffic Safety Administration: Traffic Safety Facts (1999)—Young Drivers. Washington, D.C., United States Department of Transportation, National Highway Traffic Safety Administration, DOT HS 809 099, 1999

27. Economic impact of motor vehicle crashes involving teenaged drivers—Kentucky, 1994. MMWR Morb Mortal Wkly Rep 1996;45(33):715

28. Ulmer RG, Williams AF, Preusser DF: Crash involvements of 16-year-old drivers. J Safety Res 1997;28(2):97

29. Fatal Automotive Reporting System, Web Based Encyclopedia, www-fars.nhtsa.dot.gov/queryReport.cfm?stateid=0&year=2001 [limited using age = 16, occupant in passenger compartment, vehicle other than bus, commercial truck, or motorcycle], accessed 2/24/03

30. Insurance Institute for Highway Safety: US licensing systems for young drivers. www.highwaysafety.org/safetyfacts/statelaws/grad license.htm , accessed 12/20/02

31. Shope JT, Molnar LJ, Elliott MR, et al: Graduated driver licensing in Michigan: Early impact on motor vehicle crashes among 16-year-old drivers. JAMA 2001; 286(13):1593

32. Foss RD, Feaganes JR, Rodgman EA: Initial effects of graduated driver licensing on 16-year-old crashes in North Carolina. JAMA 2001;286(13):1588

33. Insurance Institute for Highway Safety: What's wrong with this picture? Status Report, Insurance Institute for Highway Safety 2002;37(6):1

34. Williams AF, Preusser DF: Night driving restrictions for youthful drivers: A literature review and commentary. J Public Health Policy 1997;18(3):334

35. Civijanovich NZ, Cook LJ, Mann Nc, et al: A population based study of crashes involving 16- and 17-year-old drivers and the potential benefit of graduated driver licensing restrictions. Pediatrics 2001;107(4):634

36. Preusser DF, Ferguson SA, Williams AF: The effect of teenage passengers on the fatal crash risk of teenage drivers. Accid Anal Prev 1998;30(2):217

37. Chen LH, Baker SP, Braver ER, et al: Carrying passengers as a risk factor for crashes fatal to 16- and 17-year-old drivers. JAMA 2000;283(12):1578

38. National Transportation Safety Board: NTSB Acting Chairman Carmody addresses graduated driver licensing symposium; safety board issues new recommendations aimed at young drivers (press release). November 2002. www.ntsb.gov/pressrel/2002/021106.htm , accessed 2/2/03

DR. McKAY is attending physician, department of emergency medicine, Brigham and Women's Hospital, Boston, Mass.

DR. CURTIS is assistant professor, department of emergency medicine, Georgetown University Medical Center, Washington, D.C.

The authors have nothing to disclose in regard to affiliations with, or financial interests in, any organization that may have an interest in any part of this article.

Car safety: Take-home points for pediatricians

General guidance

• Every child must be properly restrained on every trip

• All children under 12 years of age should ride in the rear seat

• Children are more likely to be properly restrained if the driver is restrained

Infants under 12 months

• All infants under 12 months should ride in the rear seat in a rear-facing child safety seat; if a child has to ride in the front seat, the airbag must be turned off

• The safety seat should be firmly attached to the vehicle seat (no more than one inch of movement in any direction)

• The harness straps should come through the lower slots of the safety seat and should be snug with the chest clip connected at the level of the armpits

Children over 12 months, between 20 and 40 pounds

• Once children reach 12 months of age and weigh at least 20 pounds, they can face forward, but they should still ride in the rear seat. If a child has to ride in the front, the airbag must be turned off

• The safety seat should be firmly attached to the vehicle seat (no more than one inch of movement in any direction).

• Shoulder straps should come through the upper slots of the safety seat, just behind or over the shoulders, and should be snug with the chest clip at the armpit; there should be no more than two fingers of room between the strap and the child's body

Children between 40 and 80 pounds and under 4 feet 9 inches

• For maximum safety, these children should sit in a high-back booster and wear the regular vehicle lap and shoulder belt. They should ride in the rear seat

Children over 80 pounds and 4 feet 9 inches

• Children this size should always use the vehicle seat belt

• They should ride in the back seat until they reach 12 years of age

Children 12 years of age and older

• Children older than 12 years can ride in the front as long as they are wearing a seat belt

• Teenagers should be actively discouraged or prevented from riding with novice drivers

Teenage drivers

• Learners should have at least six months of supervised driving—including some driving at night and in bad weather—with a licensed driver over 21 years of age

• Once teenagers get a license and can drive without supervision, they should not carry passengers for at least six months, and they should be restricted from driving late at night

Resources on keeping children safe in motor vehicles

Buying a Safer Car For Child Passengers 2003 (National Highway Traffic Safety Administration)
( http://www.nhtsa.dot.gov/people/injury/childps/BASCkids2003/BASCkids_ index.html ) This publication (DOT HS 809 545, February 2003) discusses considerations relating to child safety in automobiles, compatibility of safety seats and different kinds of cars, and safety features to consider when buying a car; it also offers general advice on transporting child passengers.

NHTSA's New Car Assessment Program
(NCAP, http://www.nhtsa.dot.gov/ncap/ ) Rates new cars for safety in front- and side-impact crash tests and for rollover risk.

Insurance Institute for Highway Safety's Vehicle Ratings
( http://www.hwysafety.org/vehicle_ratings/ratings.htm ) Evaluates new cars for safety in front-, side-, and rear-impact crash tests.

National Safe Kids Campaign's online car seat locator
( http://www.safekids.org/buckleup/index.cfm ) Matches the entered size and weight of the child with the type of seat and suggests makers and models.

NHTSA's Child Safety Seats Ratings on "ease of use"
( http://www.nhtsa.dot.gov/CPS/CSSRating/ ) Rates safety seats on how easy they are to assemble, install, and fasten the child into.

NHTSA's Child Seat Safety Recall Campaign listing
( http://www-odi.nhtsa.dot.gov/cars/problems/recalls/childseat.cfm ) Enables parents to search for recalled seats and register their child's seat so they can be notified in the event of a recall. Includes a listing of vehicles recalled for problems with integral seats.

GUIDE FOR PARENTS

Tips to help you keep your child safe in the car at any age

Riding in a motor vehicle is the most dangerous thing your child does, no matter what his or her age. You can do much to prevent serious injury or death by heeding the following tips on car safety.

General tips

• EVERYONE riding in the car should be properly restrained.

• Your child is more likely to buckle up if you do.

• ALL children under 12 years of age should ride in a rear seat. If you have more children than rear seats, the oldest child should ride in the front seat with the front airbag turned OFF.

• Infant car safety seats should be tilted at an angle of about 45°, and the seat belt must be locked into position around the seat. If the seat is correctly installed, it should not wiggle more than one inch in any direction. The straps should come through the lower slots of the safety seat. They must fit snugly—you should not be able to get more than one finger between the straps and your baby's body. Be sure to put the chest protector at about the level of the baby's armpits to prevent the shoulder straps from sliding off.

• Installing a car seat properly can be difficult. You can get expert help from the following Web sites: www.nhtsa.dot.gov/people/injury/childps/CPSFitting/Index.cfm or www.carseat.org .

Age-specific tips

• Under 1 year. Babies under 1 year of age have heavy heads and relatively weak necks, which increases their risk of head and neck injuries in an accident. Babies should always ride in a car seat that faces backwards (toward the rear of the vehicle) in the back seat of the vehicle. Do not place your baby in a forward-facing car seat until he is both 12 months of age and 20 pounds.

• 1 year to 4 years. Children older than 1 year who weigh at least 20 pounds can ride facing forward but should stay in the back seat. When you install the new car seat, it should be upright and the harness straps should go through the upper slots. Newer cars will allow you to use tether systems that are much easier to install. The integral (built-in) car seats in some vehicles are usually safe for toddlers (check the owner's manual for your vehicle).

• 4 years to 8 years. Children who weigh more than 40 pounds are too big for a car seat and too small to use a regular seat belt safely. The solution is a booster seat, preferably one with a high back, which will help protect your child's head and neck. Booster seats raise your child's body a few inches above the car seat so that the regular lap and shoulder seat belt fits properly. Boosters don't have to be attached directly to the vehicle seat, which makes them easier to use than car safety seats, and they let the child see out the window—a real benefit on a long trip.

• 9 years to 12 years. Children from 9 to 12 years of age should ride in the rear seat with the seat belt worn correctly (no putting the shoulder harness behind the back or under the arm!). Children this age are much more likely to wear a seat belt if you wear yours.

• Over 12 years. Once your child is older than 12 years and at least 4 feet 6 inches tall and 80 pounds, she can ride in the front seat safely. But she still needs to wear a seat belt. Seat belts prevent more than 50% of serious injuries.

A new risk arises when your child's friends start to learn to drive. Teenage drivers have more than five times as many crashes as older drivers, and their risk of crashing goes up when they carry passengers. Your child will be safer if she doesn't ride in a car with a teenager who is a new driver.

• Teenage drivers. Some states have graduated licensing systems for teenage drivers to help protect them from the hazards of immaturity and inexperience. If your state does not have such a system, you can still help keep your teenage driver safe in several ways. After your teenager gets his learner's permit, he should drive only under adult supervision for at least six months, including some supervised driving at night and in bad weather. Once he passes the road test and gets a license, he should not carry passengers for six months. And even if he doesn't have to be home by 9 p.m., he should not drive after that time for the first year because teenage drivers have a high risk of serious crashes late at night.

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