Effect of Child Occupant Protection Laws on Fatalities
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Q U.S. Department of Transportation National Highway Traffic Safety Administration DOT HS 807 453 August 1989 NHTSA Technical Report Effect of Child Occupant Protection Laws on Fatalities This document is available to the public from the National Technical Information Service, Springfield, Virginia 22161. The United States Government does not endorse products or manufacturers. Trade or manufacturers' names appear only because they are considered essential to the object of this report. Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. DOT HS 807 453 4. Title and Subtitle 5. Report Date • Effect of Child Occupant Protection Laws on August 1989 Fatalities 6. Performing Organization Code 8. Performing Organization Report No. 7. Authors) Susan C. Partyka 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) National Center for Statistics and Analysis 400 7th Street, S.W. 11. Contract or Grant No. Washington, DC 20590 13. Type of Report and Period Covered 12. Sponsoring Agency Name and Address Research and Development NHTSA Technical Report National Highway Traffic Safety Administration 400 7th Street, S.W. 14. Sponsoring Agency Code Washington. DC 20590 15. Supplementary Notes 16. Abstruct In 1978, child safety seats and adult safety belts used by children under five years old saved 3 percent of those who would have been killed if no one had used the devices. By 1988, children's use of safety seats and belts had risen enough that 26 percent of those at risk were saved. During these eleven years, the number of states with child occupant protection laws increased from one (in 1978) to fifty (in 1985) plus- the Di'str ict of Columbia. The 1981 to 1984 fatality experience was used to estimate the incremental benefit to a state of having a child occupant protection law in any one year. During these four years, 19 percent of those who would have been killed (if no one used a safety seat or belt) in states with child occupant protection laws were saved by safety seats and belts. In contrast, only 10 percent were saved in states without laws. The difference between these two numbers (9 percent) is an estimate of the immediate benefit to a state of passing a child occupant protection law. However, because these laws contribute to the increasing use of safety seats and belts by young children, their cumulative and potential benefits are much greater. 17. Key Words 18. Distribution Statement accident data, child restraints, Document is available to the public fatalities through the National Technical Information Service, Springfield, VA 22161 19. Security Clossif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price Unclassified Unclassified 9 Form DOT F 1700.7 (8-72) Reproduction of completed page authorized Effect of Child Occupant Protection laws on Fatalities Susan C. Partyka National Center for Statistics and Analysis August 1989 Findings In 1978, child safety seats and adult safety belts used by children under five years old saved 3 percent of those who would have been killed if no one had used the devices. By 1988, children's use of safety seats and belts had risen enough that 26 percent of those at risk were saved. During these eleven years, the number of states with child occupant protection laws increased from one (in 1978) to fifty (in 1985) plus the District of Columbia. The 1981 to 1984 fatality experience was used to estimate the incremental benefit to a state of having a child occupant protection law in any one year. During these four years, 19 percent of those who would have been killed (if no one used a safety seat or belt) in states with child occupant protection laws were saved by safety seats and belts. In contrast, only 10 percent were saved in states without laws. The difference between these two numbers (9 percent) is an estimate of the immediate benefit to a state of passing a child occupant protection law. However, because these laws contribute to the increasing use of safety seats and belts by young children, their cumulative and potential benefits are much greater. Background In January 1978, the first state child occupant protection law went into effect, in Tennessee. Other states were initially slow to follow. The second law went into effect in Rhode Island, in July 1980; the third went into effect in West Virginia in July 1981. However, between January 1982 and June 1985, laws went into effect in the remaining forty-seven states and the District of Columbia. The date of the original child occupant protection law in each state is shown in Appendix Table A. Most original laws did not cover all children under five years old. Many of these laws have been strengthened since their original enactment, and thirty-four states plus the District of Columbia now also have general safety belt use laws that apply to all ages. Data In the last eleven years (1978 through 1988), between 536 and 700 children under five years old were killed in passenger vehicles each year. The agency's Fatal Accident Reporting System (FARS) provided counts of young occupants killed in cars, pickups, vans, and multipurpose vehicles. These vehicles were identified as FARS Body Type codes 1-9, 39, 43, and 50-52 for data from years 1978 through 1981 and codes 1-12, 40-41, 48-51, 53-56, 58-59, and 67-69 for data from years 1982 through 1988. - 1 i Each fatality was classified by whether it occurred when and where a state child occupant protection law was in effect. For this purpose, all child passenger vehicle occupant fatalities that occurred in a state whose law went into effect sometime that month were considered to have been covered by the law. All children under five years old were included, whatever the specific age or other coverage provisions of the law in that state at that time. The children were separated into two age groups: "infants" (those under one year old) and "toddlers" (those one through four years old). This distinction was made because of differences, by age, in the types of child occupant protection devices that are available (safety seat type) and the type chosen (safety seat or adult safety belt). Each child was classified by his use of a safety seat or belt, as reported by the police. There were a few children reported to have been protected by an unspecified type of device. These children were grouped with children in safety belts. There were many more children for wham it was unknown whether they were using any type of device at all. These were prorated among the categories of no device, safety seat, and safety belt. Results The fatality data, classified by year, law coverage, child age, and police-reported occupant protection device are shown in Appendix Table B. The estimated number of child fatalities by type of device used (with unknown data prorated among the categories for none used, safety seat, and safety belt) are shown in Appendix Table C. These estimates are shown with one decimal place to help the reader follow the subsequent calculations of lives saved. It has been estimated that safety seats and belts save lives when used (Lives Saved by Child Restraints from 1982 through 1987, S. Partyka, NIMA, DOT-HS-807-371, December 1988). Child safety seats are very effective in preventing fatality when the child is properly secured in the seat and the seat is properly attached to the vehicle. Unfortunately, many children do not receive the full benefit of their safety seat because of incorrect (or partially incorrect) use. However, even with the mix of correct, partially correct, and incorrect use of the 1980's, it is estimated that: child safety seats prevented 69 percent of infant fatalities, child safety seats prevented 47 percent of toddler fatalities, and adult safety belts prevented 36 percent of child fatalities when used. The number of children saved by safety seats and belts was estimated from the estimated effectiveness of these devices in preventing fatality as: Lives Saved = Fatalities * Effectiveness / (1 - Effectiveness). The theoretical number of children at risk of fatality can be defined as the number who would have been killed if no child used a safety seat or belt. This is the sum of the total number killed and the number of lives saved by safety seats and belts. The proportion saved was calculated as the number saved divided by the number at risk. These results are shown in Appendix Table C. 2 The percentage of children at risk of fatality who were saved by safety seats and belts increased from an estimated 3 percent in 1978 to 26 percent in 1988. The results are shown in Table 1 and Figure I. CcTiparing the estimated lives saved for children covered, versus not covered, by state occupant protection laws suggests the incremental benefit to a state of having a law that year. The results are summarized in Table 2 and Figure 2. Table 1: Young Child Occupants Saved by Safety Seats and Belts Percent Saved, of those at Risk of Fatality Year Overall With Law Without Law 1978 3.4 0.0 3.5 1979 6.0 0.0 6.2 1980 6.2 25.9 5.5 1981 9.6 18.2 9.4 1982 10.5 15.8 9.4 1983 14.7 17.7 11.8 1984 18.6 20.6 9.1 1985 21.2 21.2 1986 21.6 21.6 1987 23.9 23.9 1988 26.5 26.5 Figure 1: Young Child Occupants Saved by Safety Seats and Belts 30 25 20 Nai 15- 6 c m a 10 5 0 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 Year Table 2: Comparison of Percentage of Child Occupants Saved Year Four Percent Saved: 1981 1982 1983 1984 Years With Law 18.2% 15.8% 17.7% 20.6% 19.0% Without Law 9.4% 9.4% 11.8% 9.1% 9.9% Difference 8.8% 6.4% 5.9% 11.5% 9.1% Figure 2: Young Child Occupants Saved by Safety Seats and Belts -- by State Law Coverage 30 25- Covered by Law 20- fn >> 15- c a> All a> ^ 0 10_ _ ^° --_ Not Covered by Law 5 0 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 Year From 1981 to 1984, the percent of children saved by safety seats and belts in states with child occupant protection laws was 9 points higher than in states without laws.