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| Misuse of Child Safety Restraints (part 3) |
Home / Traffic Safety / Buckle Up America / Misuse of Child Safety Restraints (part 3)
3.0 Results and Analysis This chapter presents sample characteristics; observed restraint use and misuse; and other findings from the observation study. (It should be noted that percentages in Tables may not add up to 100 percent as a result of rounding.) 3.1 SAMPLE SIZE CHARACTERISTICS A total of 4,126 vehicles and 5,527 children less than the driver-estimated weight of 80 lb were included in the study. Table 3 identifies the sample size by State and the total.
The 5,527 children in the sample included 511 children less than 20 lb (9.2%); 2,483 children from 20 to 39 lb (44.9%); and 2,533 children from 40 to 79 lb (45.8%). Table 4 presents the number of sampled children by weight from each State and the total.
The age categories of the children weighing less than 80 lb are presented in Table 5, by State. There were 676 children less than 1 year of age; 2,021 children 1 through 3 years of age; 2,571 children 4 through 8 years of age, and 259 children age 9 and older.
3.2 VEHICLE SEATING POSITION OF CHILDREN The vehicle seating position of the 5,527 sampled children less than 80 lb was observed and recorded. Only 9.4% of the children were in the front seat and most of these were seated on the outboard passenger side (7.8%) as opposed to the front center position (1.6 %). Most children were in second row seats (84.8%). This included 30.4% on the left side (behind the driver); 21.2% in the second row middle position; and 33.2% in the second row right side position (passenger side). In addition, 5.5% of the children were in the third row seats of minivans or sport utility vehicles; and 0.4% of the children were in the area behind the third row seats of a minivan or in the cargo area of a pickup truck. 3.3 CHILD RESTRAINT SYSTEM (CRS) USE Of the 5,527 children less than 80 lb, 62.3% were in a CRS, 25.9% were in a vehicle SB, and 11.8% were unrestrained. Table 6 presents the restraint type by each State and the total sample.
The number of children in a CRS, SB, or unrestrained across the six States is shown in Table 7 for each of four weight categories. For the 511 children less than 20 lb, 97.1% were in a CRS. For the 2,483 children 20 to 39 lb, 86.4% were in a CRS, 6.3% were in a SB, and 7.2% were unrestrained. For the 1,704 children 40 to 59 lb, 41.7% were in a CRS, 43.1% were in a SB, and 15.2% were unrestrained. For the 829 children 60 to 79 lb, only 10.9% were in a CRS, 64.9% were in a SB, and 24.2% were unrestrained. Type of Restraint Used (By Weight)
A comparison of all children less than 60 lb with the previous NHTSA CRS observation study by Decina and Knoebel (1996) is shown in Table 8. The comparison shows that overall restraint use improved by only 3.3% since the previous study. However, CRS use greatly improved by 20.9%. There were also fewer unrestrained children (by 3.2%). (Data were collected in the Spring of 1995 for the previous study, compared with the Fall of 2002 for data collected in this study.) Comparison of current and past NHTSA CRS misuse observation studies. (Children less than 60 lb only data)
The number of children in a CRS, SB, or unrestrained is shown in Table 9 for each of the 4 age categories. For the 676 children less than 1 year of age, 97.3% were in a CRS. For the 2,021 children 1 through 3 years of age, 90% were in a CRS, 3.6% were in a SB, and 6.4% were unrestrained. For the 2,571 children 4 through 8 years of age, 37.2% were in a CRS, 45.5% were in a SB, and 17.3% were unrestrained. For the children age 9 and older who weighed less than 80 lb, 3.1% were in a CRS, 72.6% were in a SB, and 24.3% were unrestrained. Type of restraint used by age. (Children weighing less than 80 lb)
Comparison with the NHTSA National Occupant Protection Use Survey (NOPUS2), which provides the only National probability based observation data on the use of child restraints (CRS or SB) on the Nation"s roads, revealed results similar to this study. (NOPUS data were collected in June 2002. Observation data for this misuse study were primarily collected in October and November 2002.) NOPUS found 99% of infants (children less than 1 year of age) restrained (CRS or SB), compared to this study"s 97.5% restrained (CRS or SB). NOPUS found 94% of children ages 1 through 3 restrained (CRS or SB), compared to this study"s 93.6% restrained (CRS or SB). NOPUS found 83% of children ages 4 through 7 restrained (CRS or SB), compared to this study"s 82.7% of children ages 4 through 8 restrained (CRS or SB). The number of children less than 80 lb riding restrained in various types of CRSs (i.e., infant, convertible, forward-facing only, belt-positioning booster, shield booster, other types) as well as a SB, and riding unrestrained is shown in Table 10 for each weight category. Almost 90% of the children less than 20 lb were either in an infant seat or riding in a rear-facing position in a convertible child safety seat. About 70% of children 20 to 39 lb were either in a forward-facing only child safety seat or riding forward-facing in a convertible seat. However, fewer than half of children 40 to 59 lb (about 40%) were in a convertible seat, forwardfacing only seat, or booster seat. Barely 10% of children 60 to 79 lb were in a child restraint of any type. Table 11 shows, by age category, the number of children less than 80 lb who were restrained in various types of CRSs, as well as those restrained in a SB and those unrestrained. The results are similar to those for the weight data. More children were either in SBs or unrestrained as their age increased. Only about 22% of booster-age children (4 through 8) were in a booster seat. Type of Child Restraint Used by weight (part a)*:
*Chart is continued below. **Convrt R-F (Convertible seat rearward facing) ***Convrt F-F (Convertible seat forward facing) Type of Child Restraint Used by Weight (part b):
*Integrated Seats, Laptops Type of Child Restraint Used by Age (part a*):
*Chart is continued below. **Convrt R-F (Convertible seat rearward facing) ***Convrt F-F (Convertible seat forward facing) Type of Child Restrain Used by Age (part b):
*Integrated Seats, Laptops 3.4 CHILD RESTRAINT SYSTEM (CRS) MISUSE CRS misuse measures based on potential for causing injury were identified at the workshop with child passenger safety experts. These critical CRS misuse measures were used to develop the data collection instruments and observation guidelines that were then finalized at the train-the-trainer workshop. The critical areas identified for observation were appropriateness of CRS type by age, weight, and height characteristics; CRS installation in the vehicle (i.e., proximity to air bag, direction of seat, vehicle SB tightness, use of LATCH); and placement of the child in the CRS (i.e., harness strap tightness and connection). One of the most important findings from the study is the percentage of CRSs with a critical misuse. Of the 3,442 CRSs observed in this study, 72.6% displayed one or more types of critical misuse. For the total sample of CRSs observed in the study, the percentage of CRSs exhibiting critical misuses, by CRS type is shown in Table 12. Percentage of CRSs exhibiting critical misuses, by CRS type.
The most common CRS misuses were loose vehicle SB attachment to the CRS and loose harness straps securing the child to the CRS. Misuse by CRS type and each critical misuse element is presented in Tables 13 through 19. The critical misuses are not mutually exclusive. In many cases, more than one critical misuse was observed on a CRS. Definitions of the critical misuse measures used in the study are provided below. CRITICAL MISUSE DEFINITIONS Age/fit inappropriateness: The child"s weight or age does not meet the criteria for the CRS being used. Harness strap not used: Self-explanatory Head restraint needed: The child"s head is above the back of the vehicle seat. (A high-back booster seat is needed.) Improper fit of vehicle shoulder belt in booster seats: The vehicle shoulder belt is loose, or does not cross the center of the shoulder, or cuts into or crosses the neck, throat, or face. Also includes belt placed under the arm, behind the back, or not touching the torso. Improper fit of vehicle lap belt in booster seats: The vehicle lap belt is loose and/or the lap belt is positioned across the child"s stomach (instead of across the upper thighs/lower hips) Improper harness belt paths/slots: Based on the child"s size, the harness straps are not in the correct CRS harness slots. Improper position of harness strap: Harness strap is tucked under the arm of the child. Improper use of locking clip to SB: On vehicles with a sliding latchplate on the SBs, the locking clip is more than 1 inch away from the SB"s latchplate. Improper vehicle SB path/slots: Vehicle SB is not correctly routed through the CRS slots for the SB. Incorrect seat direction: Self-explanatory Location of CRS: A rear-facing CRS is installed in front of an active airbag. Loose harness straps: The harness strap has more than 1 finger"s slack. Loose vehicle SB: The CRS can move more than 1 inch when checked at the belt path. Unbuckled harness strap: Self-explanatory Unbuckled vehicle SB: Self-explanatory Visible damage to CRS: Crack in the shell, broken harness parts, frayed harness straps, torn padding. Critical Misuses of Infant Seats*:
*The sample size was 497, unless otherwise noted due to missing data. Missing data noted by (n=). There were 137 children greater than 20 pounds but less than 1 year of age in a CRS. Of this sample, 27.7% were facing the wrong direction (forward). Critical misuses of rear-facing convertible seats.*
*The sample size was 140, unless otherwise noted due to missing data. Missing data noted by (n=). Critical misuses of forward-facing convertible seats.*
*The sample size was 1,247, unless otherwise noted due to missing data. Missing data noted by (n=). Critical misuses of forward-facing only seats.*
*The sample size was 766, unless otherwise noted due to missing data. Missing data noted by (n=). Critical misuses of belt-positioning booster seats.*
*The sample size was 664, unless otherwise noted due to missing data. Missing data noted by (n=). Critical misuses of shield boosters.
Critical misuses of forward-facing integrated seats.
3.5 HARNESS RETAINER CLIP MISUSE Even though harness retainer clip misuse was not identified as a critical misuse at the expert workshop, the State site coordinators and their field site managers felt it was important to include the misuses relating to the harness retainer clip as an observation measure in the study. Harness retainer clips are found on many (but not all) infant, convertible, forward-facing, and integrated seats for children less than 40 lb. If the harness retainer clip was not connecting the harness straps together at armpit level, correctly threaded and free from damage or alteration, it was coded as a misuse. This misuse was checked on the 2,672 CRSs that could have a harness retainer clip. Overall misuse (with harness retainer clip misuse included) for each type of CRS which uses a harness retainer clip is shown in Table 20. Because other harness misuse measures were usually associated with harness retainer clip misuse, the inclusion of harness retainer clip misuse made little difference in the overall misuse measure. Harness retainer clip misuse by CRS type.
3.6 OTHER CHILD RESTRAINT SYSTEM (CRS) MISUSE TYPES AND LATCH USE The data collection teams also recorded whether the CRSs were visibly damaged, whether the CRS base extended too far beyond the vehicle seat, and whether there were aftermarket devices or extraneous items on the CRS or SB. There were 114 visibly damaged CRSs observed in the study (crack in the shell, broken harness parts, frayed harness straps, torn padding). Of these, 68 were forward-facing convertible seats, 19 were forward-facing only seats, 12 were belt-positioning booster seats, 10 were infant seats, 3 were shield boosters, and 2 were rear-facing convertible seats. The study considered visible damage to be a critical misuse. There were 80 CRSs with the base of the CRS extending beyond the vehicle seat more than 20%. This type of misuse was not considered critical misuse in the study. In addition, there were 102 CRSs with aftermarket devices or extraneous items either on the CRS or in the vehicle. These included toys on harness straps, blankets behind the child"s back, and plastic mat under the CRS. Observations were also made on the use of the LATCH System (Lower Anchors and Tethers for CHildren) for CRS installation to the vehicle seat. LATCH installations were identified in 42 vehicles (of a total of 4,126 vehicles). Field observers found three cases of improperly used lower anchors; three cases of improperly used tethers, and six cases of the vehicle SB and the lower anchor being used together. 3.7 SAFETY BELT (SB) ONLY USE BY CHILDREN Of the 5,527 children less than 80 lb, 25.9% (1,431) were in a SB. The majority of these SB users (80.9%) were in a lap/shoulder belt combination; 17.5% were in a lapbelt-only system; and 1.1% were in a shoulder-belt-only system. Field observers recorded inappropriate fit of the SB on children according to the proper use definitions (see Appendix A). For 1,158 lap/shoulder belt combinations observed, the SB did not fit the child in 68.5% of the cases. For the 250 lap-belt-only systems observed, the lap belt did not fit the child in 70.4% of the cases. For the 16 shoulder-belt-only systems observed, the shoulder belt did not fit the child in 87.5% of the cases. There were 7 children in SBs in which type of SB was unrecorded. 3.8 UNRESTRAINED CHILDREN Of the 5,527 children less than 80 lb, 11.8% were unrestrained. The percentage of unrestrained children increased with each heavier weight category of children. For the 511 children less than 20 lb, 2.7 were unrestrained. For the 2,483 children 20 to 39 lb, 7.2% were unrestrained. For the 1,704 children 40 to 59 lb, 15.2% were unrestrained. And for the 829 children 60 to 79 lb, 24.2% were unrestrained. 3.9 DRIVER CHARACTERISTICS Of the 3,752 drivers observed for SB use, 77.4% were restrained. When the driver was wearing a SB, 91.7% of the children less than 80 lb were restrained in either a CRS (44.2%) or a SB (47.5%). Only 8.3% of children less than 80 lb were unrestrained when the driver was restrained. When the driver was not wearing a SB, 62.3% of the children less than 80 lb were restrained in either a CRS (43.2%) or a SB (19.1%). Another 37.7% of the children were unrestrained when the driver of the vehicle in which they were riding was unrestrained. The relationship in NOPUS of driver restraint use to child restraint use was very similar to the findings of this study (see description of NOPUS study on page 28). NOPUS found that when the driver was belted, 92% of observed children under age 8 were restrained (CRS or SB), compared to 91.7% of children less than 80 lb restrained (CRS or SB) in this study. NOPUS found that when the driver was unbelted, 72% of the observed children under age 8 were restrained, compared to 62.3% of children less than 80 lb restrained in this study (Glassbrenner, 2003). Drivers were questioned regarding CRS acquisition (new or used). For 90% of the CRSs observed, drivers indicated that the CRS was obtained new. Only 10% of the seats observed were obtained used. Drivers were not asked if the CRS had been involved in a crash. 3.10 AIR BAG SYSTEM CHARACTERISTICS Air bag systems were also observed and recorded. Field observers were able to identify the vehicle occupant protection system for most of the total vehicle sample. Among the vehicles where the air bag system could be determined:
The status of air bag switches was also observed and recorded. For 88 vehicles checked for the position of the on/off switch, 51 vehicles had the switch "on" and 37 vehicles had the switch "off." Sixteen children less than 80 lb were in the front seat of vehicles with the air bag switch in the "on" position. Of the 16 children, 2 were in rear-facing CRSs, 4 were in forwardfacing seats, 3 were in SBs, and 7 were unrestrained. |
| Author - | Lawrence E. Decina and Kathy H. Lococo for the NHTSA |
| Published - | 5/1/2003 |
| Publisher - | The National Traffic Safety Administration |
| On the web - | http://www.nhtsa.dot.gov |
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