Skip to main content
You can also sort pages by filters.
Table of Contents
Download the Full Book

Effectiveness: 5 Star Cost: $
Use: High
Time: Short

Beginning with Tennessee, every State from 1978 to 1985 passed laws requiring children traveling in motor vehicles to be restrained in child restraints appropriate for the child’s age and size (Kahane, 1986). Today, State child restraint laws vary in terms of who is covered by the law, the types of restraints required, and whether children are required to ride in the rear seat. In some States, children as young as 5 may be restrained using the adult seat belt, while other State laws require children up to age 9 or 80 pounds or 57 inches tall to be restrained in a child restraint or booster seat (GHSA, 2019b; IIHS, 2019a, 2019b). Research has shown that laws requiring a child restraint or booster seat for children 4 to 7 are associated with a decrease in fatalities (Mannix et al., 2012).

In general, young children are usually covered by child restraint laws, while older children and adults are covered by seat belt laws. However, in 4 States some children under 16 are covered by neither law (IIHS, 2019a, 2019b). This seems to arise from the specific wording of laws in certain States that exclude some young occupants (perhaps inadvertently) because of a particular combination of age, height, or seating position. Most child passenger safety laws are primary; however, most seat belt laws start coverage before a child reaches 18, so older children and teens might be covered by a secondary enforcement seat belt law in some States. Research has found that teens living in a secondary enforcement State are less likely to report wearing their seat belt than teens living in primary enforcement States (Garcia-Espana et al., 2012). Strong occupant restraint use laws should be comprehensive, covering all seating positions equipped with a seat belt in all passenger vehicles (ACTS, 2001; NCUTLO, 2000; NHTSA, 2003). Such a law sends a clear and consistent message to the public. NHTSA and  partners have encouraged States to expand their child restraint laws to include “booster” provisions that cover children until they are big enough for the lap and shoulder belts to fit properly.

Use: As of November 2018, all but one State had enacted child restraint laws covering children through at least age 5 (South Dakota’s law only covers children 4 and younger) (IIHS, 2019a, 2019b). However, a wide variation in age, height, and weight requirements exists among the laws of the  States (GHSA, 2019b; IIHS, 2019a, 2019b).

Effectiveness: Research conducted by Arbogast et al. (2009) found that transitioning children from child restraints with harnesses to belt-positioning booster seats instead of vehicle seat belts provides significant safety benefits for children at least through 8, and that belt-positioning booster seats lower the risk of injury to children in crashes by 45% compared to the use of vehicle seat belts alone. Some studies evaluated the effect of booster provisions in States’ laws on booster seat use (Gunn et al., 2007). Observational surveys conducted in Washington State before their booster seat law was expanded found that only 21% of children from ages 4 to 8 were using booster seats (Ebel et al., 2003). Following a new law requiring booster seats for children weighing from 40 and 60 pounds or younger than 6 years old, observational surveys in Washington State found close to half of children 4 to 8 years old in a booster seat (Stehr & Lovrich, 2003). Similarly, an observational study of child restraint legislation in Canadian provinces found that provinces with newly passed legislation saw booster/front-facing restraint use increase to 54% from 26% previously (Simniceanu et al., 2014). However, during the same period, provinces with existing legislation saw no increase (31% versus 30%). This suggests that legislation on its own may be insufficient, and that the outreach, education, and enforcement  associated with new legislation play a vital role in increasing restraint use. Another Canadian study found that a new booster-seat law was associated with a 10.8% reduction in motor-vehicle injuries among children 4-8 (Brubacher et al., 2016). The National Survey of the Use of Booster Seats found that booster seat use has remained relatively stable, despite the enactment of laws to encourage the use of booster seats (Li & Pickrell, 2018b). Booster seat use by 4- to 7-year-olds in 2017 was 40%, a non-significant change from 41% in 2006, the first year of the survey.

One study evaluated the effects of Tennessee’s “booster” provisions that added new requirements for 4- to 8-year-olds in 2005 (Gunn et al., 2007). Pre- and post-law observational survey data revealed a significant increase in booster seat use among 4- to 8-year-olds from 29% to 39%. Decina et al. (2008) reported that an observational study conducted to evaluate a demonstration program found a 9-percentage-point increase in the use of child restraints, including booster seats, for children 4 to 8 following enactment of an enhanced child restraint law (booster seat law) in Wisconsin. Similarly, a second evaluation of Wisconsin’s booster seat law found that while total booster seat use did increase, the law did not impact all children equally. Specifically, use of booster seats and proper use of booster seats varied among different racial and socioeconomic groups suggesting that further study is needed of the effects of booster seat legislation on all children (Brixey et al., 2011).

Several research studies (Fell et al., 2005; Margolis et al., 1996) have found restraint use levels among children and teens covered by restraint use laws are higher than those not covered, and that injury levels among children covered by child passenger safety laws are lower than children not covered.

Costs: The costs of expanding a restraint use law to include all seating positions in all passenger vehicles are minimal.

Time to implement: Expanded restraint use law coverage can be implemented as soon as the law is enacted and publicized.

Other issues:

  • Elements of child/youth occupant restraint laws: The scope and wording of these laws may affect proper use of child restraints. An analysis of NASS-GES crashes involving children in not-at-fault vehicles examined predictors of restraint use (Benedetti et al., 2017). This study employed an “induced exposure” approach that approximates a random sample in the driving population. The study found that children were more likely to ride in the recommended type of restraint if their State’s child/youth occupant restraint law followed best practices for child occupant protection (i.e., AAP, 2011). However, State laws did not seem to affect whether or not a child was restrained at all. The strongest predictor of unrestrained children in this study was an unrestrained driver (see also Raymond et al., 2018). This reinforces longstanding research findings of a direct correlation between adult and child occupant restraint status, including Starnes (2003).