Verification of the Laser Powder Bed Fusion Performance of 2024 Aluminum Alloys Modified Using Nano-LaB6.

The application of 2024 aluminum alloy (comprising aluminum, copper, and magnesium) in the aerospace industry is extensive, particularly in the manufacture of seats. However, this alloy faces challenges during laser powder bed fusion (PBF-LB/M) processing, which often leads to solidification and cracking issues. To address these challenges, LaB6 nanoparticles have been investigated as potential grain refiners. This study systematically examined the impact of adding different amounts of LaB6 nanoparticles (ranging from 0.0 to 1.0 wt.%) on the microstructure, phase composition, grain size, and mechanical properties of the composite material. The results demonstrate that the addition of 0.5 wt.% LaB6 significantly reduces the average grain size from 10.3 µm to 9 µm, leading to a significant grain refinement effect. Furthermore, the tensile strength and fracture strain of the LaB6-modified A2024 alloy reach 251 ± 2 MPa and 1.58 ± 0.12%, respectively. These findings indicate that the addition of appropriate amounts of LaB6 nanoparticles can effectively refine the grains of 2024 aluminum alloy, thereby enhancing its mechanical properties. This discovery provides important support for the broader application of 2024 aluminum alloy in the aerospace industry and other high-performance fields.

Interior automobile seats: A syntactical and perceptual study.

This study investigated the seat layout of automobile interiors and its impact on the fluidity and privacy of interior space using spatial perception and space syntax research methods. The interior of an automobile is a typical "miniature" passenger space. First, to explore the perception characteristics of interior space fluidity and privacy across different seat configurations, we conducted a perception experiment on the interior space of seven automobile models with various seat layouts. The depth, connection, global integration degree, and standardized integration degree values were obtained using spatial syntax to perform topological calculations on the experimental automobile models. We conducted a correlation analysis in conjunction with the results of the perception experiment and the spatial syntax analysis. The calculation results of spatial syntax analysis are consistent with the experimental results of perception of automobile interior space layout on the fluidity and privacy. The different layout of automobile seats can affect people's perception on the fluidity and privacy of automobile interior space. At the same time, spatial syntax can provide an effective design analysis tool for the fluidity and privacy of automobile interior space.

Investigating the effect of hot and cold polyurethane foam on reducing whole body vibration of forklift operators.

BACKGROUND: Vibration is one of the harmful factors for forklift drivers. The use of non- standard seats and not paying attention to how the seats are maintained can be affected by the amount of vibration transmitted to the person. OBJECTIVE: This study investigates the amount of vibration transmitted from the forklift and the effect of different types of polyurethane foam in reducing the vibration transmitted from the forklift seat. METHODS: This descriptive-analytical study was performed on 38 forklifts in 4 diesel models with the same weight class. The amount of vibration transmitted from forklift seats according to ISO2631 standard, taking into account the effect of various factors such as foam type (hot and cold), thickness (6-12 cm), load and year Function was measured. The amount of vibration caused by the forklift on the seat and under the seat was evaluated using ISO7096 standard. RESULTS: The average total vibration of the whole body in all foams in no-load mode is more than with load. The transmission vibration of cold polyurethane foam is less than that of hot polyurethane foam. With increasing thickness, the efficiency of cold polyurethane foam increases by 12 cm and in the loaded state 40.63% and in the unloaded state 49.58% in reducing the vibration transmitted to drivers. CONCLUSION: The results of this study show that cold foam has better effectiveness and efficiency than hot polyurethane foam. Also, the thicker the foam, the less vibration is transmitted to the driver.

Parents' Knowledge, Attitudes, and Practices Regarding Baby Walkers, Baby Car Seats, Oral Health, and Child Screen Time in Saudi Arabia: A Cross-Sectional Study.

Background Awareness of age-appropriate milestones and developmental stages is crucial for parents to identify any potential delays or concerns early on and seek appropriate interventions. This study aimed to assess the knowledge, attitudes, and practices of caregivers in Saudi Arabia regarding baby walkers, baby car seats, early dental visits, and screen time for young children. Methods A cross-sectional survey was conducted among parents in Saudi Arabia using a structured questionnaire. A convenience and snowball sampling method was employed to recruit participants from various regions of the country. The questionnaire aimed to assess parents' knowledge regarding the recommended use of baby walkers and baby car seats, their awareness of the importance of early dental visits, and their understanding of appropriate screen time guidelines. Additionally, the survey explored parents' practices toward these recommendations. Descriptive statistics were used to analyze the data, and associations between variables were examined using the chi-squared test. Results A total of 1318 participants were included. The analysis revealed that the majority of the participants (n=1066,81.3%) use a baby walker, while only (n=292,22.3%) consider that they should never be used. Overall, (n=388,29.6%) of the participants never used a car seat for their infants or children. In terms of early childhood dental visits, approximately (n=518,39.5%) of the participants reported actually taking their child to the dentist within the recommended timeframe. Regarding screen time for children, (n=148,11.3%) of the participants reported that their children spend >5 hours daily in front of the screen.  Conclusions Raising parents' awareness about recent childcare recommendations and safe practices is crucial for promoting optimal child development, preventing health problems, facilitating evidence-based decision-making, reducing risks, enhancing parental confidence and empowerment, and nurturing positive parent-child relationships.

No Representation Without Compensation: The Effect of Interest Groups on Legislators' Policy Area Focus.

Interest groups seek to influence parliamentarians' actions by establishing exchange relationships. We scrutinize the role of exchange by investigating how interest groups impact parliamentarians' use of individual parliamentary instruments such as questions, motions, and bills. We utilize a new longitudinal dataset (2000-2015) with 524 Swiss parliamentarians, their 6342 formal ties to interest groups (i.e., board seats), and a variety of 23,750 parliamentary instruments across 15 policy areas. This enables us to show that interest groups systematically relate to parliamentarians' use of parliamentary instruments in the respective policy areas in which they operate-even when parliamentarians' time-invariant (fixed effects) and time-variant personal affinities (occupation, committee membership) to the policy area are accounted for. Personal affinities heavily moderate interest groups' impact on their board members' parliamentary activities. Moreover, once formal ties end, the impact of interest groups also wanes. These findings have implications for our understanding of how interest groups foster representation in legislatures.

Effect of naturalistic seating postures and seatbelt routing on booster-seated Q6 ATD kinematics and kinetics in frontal impacts.

RESEARCH QUESTIONS / OBJECTIVE: Test protocols evaluate restraint performance with pediatric ATDs placed in an ideal seating posture. However, real-world evidence suggests that ideal test conditions do not always reflect actual occupant positions. Prior studies have also shown that booster seat designs affect the position of the seatbelt around the child. Occupants in naturalistic seating postures, coupled with potentially unfavorable seatbelt positions, could result in adverse kinematics and kinetics in a crash. Therefore, the aim of this study was to quantify the effect of different naturalistic seating postures on the response of the Q6 ATD restrained on boosters with varying initial static belt fit in a frontal impact. METHODS/DATA SOURCES: The Q6 ATD was positioned on two booster seats of similar design but varying static belt fit metrics in three seating postures: reference, leaning forward, and leaning inboard. These booster seats were chosen from extensive belt fit studies on human volunteers and ATDs, and were defined as follows:The booster-seated ATD was restrained on the simulated Consumer Reports test buck (2010 Ford Flex 2nd row seat) with a front blocker plate using a 3-point lap-shoulder belt with a retractor and pretensioner. The sled environment was subjected to the FMVSS 213 frontal impact pulse, and each booster and seating posture was evaluated twice (n = 12 sled tests). Kinematic and kinetic measures were recorded. A linear regression analysis was conducted across postures on each booster. Further, a paired t-test analysis was conducted across booster seats for each seating posture. RESULTS: Across seating postures, the reference posture exhibited similar or higher kinematic and kinetic metric values compared to the leaning forward and leaning inboard postures on both boosters. However, both leaning forward (Booster A = 279.5 ± 21.6 mm; Booster B = 298.8 ± 1.5 mm) and leaning inboard (Booster A = 308.7 ± 1.1 mm; Booster B = 331.4 ± 8.5 mm) postures generally resulted in greater head excursion than the reference posture (Booster A = 285.0 ± 16.9 mm; Booster B = 288.1 ± 1.5 mm), indicating greater potential for head contact. Between boosters, Booster A resulted in significantly lower head 3 ms clip acceleration (p = 0.0026), HIC15 (p = 0.0008), upper neck tensile force (Fz)(p = 0.0057), chest 3 ms clip acceleration (p = 0.0013), and right abdominal pressure (p = 0.0163), and significantly higher left ASIS force (Fx)(p = 0.0150) and left (p = 0.0489) and right (p = 0.0088) ASIS moment (My) than Booster B. Upper neck tensile forces on Booster B crossed the 20% and 50% thresholds for AIS3 + injury. Lower abdominal pressure and higher ASIS forces and moments on Booster A suggest that the lap belt loaded the ASIS appropriately, and hence, relatively better kinematics than Booster B. SIGNIFICANCE OF RESULTS: This study shows that booster design affects static belt fit which can have an effect on dynamic crash performance and assessment criteria. By connecting static belt fit to dynamic performance, these effects may have the potential to help guide booster seat design.

Safety priorities for occupant protection in rear impacts.

OBJECTIVE: Rear-impact electronic cases were reviewed for serious injury to rear-seated children and adults to identify mechanisms of injury and consider priorities, countermeasures and safety concepts. METHODS: 1997-2015 NASS-CDS and 2017-2020 CISS electronic cases were analyzed for serious injury (MAIS 3+F) to rear-seated children 0-14 yo (years old) and adults 15+ yo in rear impacts. RESULTS: 31 children and 43 adults were identified with serious injury. 86.0% of child injury was related to intrusion of rear structures with injury by direct force (55.3%), compression into front interior (27.5%) or acceleration into impact (3.2%). 14.0% of injury was not related to intrusion with front-seatback rotation (12.3%) or direct force (1.7%). Only 45.1 ± 17.6% of injured children were properly restrained. 68.0% of adult injury was related to intrusion of rear structures with injury by direct force (46.2%), compression into front interior (15.3%) and acceleration into impact (6.4%). 21.6% of injury was not related to intrusion with front seatback rotation (2.5%) or direct force (19.1%). 10.4% was from ejection and ground impact without seatbelt use. Only 17.8 ± 7.5% of injured adults were restrained. Priorities, countermeasure and concepts were considered to improve occupant protection in rear impacts: 1) new rear impact test with the IIHS high-hood barrier offset to the rear at 55 mph to reduce rear-seat intrusion, 2) stepped-up campaigns for proper child seat selection and use, particularly for infants and toddlers <2 yo and adult use of seatbelts in rear seats, 3) adoption of FMVSS 201L to reduce head injury risks of children impacting the rear interior below the beltline, 4) improved front seats by shifting restraining forces from the seatback to the cushion frame with an anti-ramping guide that retains the pelvis on the seat and reduces seatback rotation, 5) changes in front seatbelts to provide early restraint of occupant movement by a rear-impact pretensioner that moves the lap-belt anchors and gives a favorable angle for early lap-belt restraint or a rear wrap-around lap belt so the occupant moves into the belt in a rear impact, 6) implementation of kinematic controls on front-occupant movement that reduces ramping in severe rear impacts, 7) guarding the area around rear-seated child with an after-market ring structure that maintains space around the child and blocks rearward rotation of the front seatback and 8)-25) recommendations. CONCLUSIONS: The primary mechanism for injury to rear-seated children and adults is intrusion, often without appropriate occupant restraint. There are priorities to improve protection by reducing intrusion, guarding the area around children, shifting front-occupant loads to the cushion frame and improving occupant restraints.

Quasi-static methods to evaluate seat strength in rear impacts.

OBJECTIVE: Various methods have been used in the past 50 years to apply Quasi-static load to a seat in the rear direction and measure seat performance in rear impacts. This study compared five of the most-common test procedures to evaluate seats. In addition, occupant mass and center of gravity are discussed as important characteristics of rear loading of seats. METHOD: Data was collected and analyzed from five different seat pull tests, including FMVSS 207, modified FMVSS 207, QST, body block and FRED II. Test data included peak force, moment and angle at peak moment. Occupant loading height of was determined using body segment weights and position in the forward (x) and vertical (z) directions based on anthropometry data. RESULTS: Some of the inherent differences in the tests are shown by comparing data with the same seat structure. The QST and FRED II use a lower height of loading than FMVSS 207. The QST and FRED II peak moment and force did not coincide with the same seatback angle as in FMVSS 207 and body block testing. Center of gravity height varies depending on whether the whole body or only the upper torso is considered. For the 50th male, it is 171.5 mm (6.8") with the whole body and 246.7 mm (9.7") with the upper torso. CONCLUSION: Results from different tests cannot be readily compared because of different loading conditions, including body shape and height of load about the H-point, which can cause the seat structure to respond differently.

High levels of synthetic antioxidants and ultraviolet filters in children's car seats.

Forty-seven compounds among synthetic phenolic and amino antioxidants and ultraviolet filters, three suites of widely used chemical additives, were measured in eighteen popular children's car seats (fabric, foam, and laminated composites of both layers) marketed in the United States in 2018. Significantly higher levels of target compounds were found in foam and composite samples than in fabric samples. Median total concentrations of phenolic antioxidants and their transformation products ranged from 8.11 µg/g in fabric to 213 µg/g in foam In general, isooctyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (AO-1135) and 2,4-di-tert-butylphenol (24-DBP) were the most abundant among all target compounds with maximum levels of526 µg/g in composite and 13.7 µg/g, respectively. The total concentrations of amino antioxidants and their transformation products and of ultraviolet filters were at least one order of magnitude lower than those of phenolic antioxidants, with medians of 0.15-37.1 µg/g and 0.29-1.81 µg/g, respectively, in which the predominant congeners were 4-tert-butyl diphenylamine (BDPA), 4,4'-di-tert-butyl diphenylamine (DBDPA), 4-tert-octyl diphenylamine (ODPA), 2,4-dihydroxybenzophenone (BP-1), 2-hydroxy-4-methoxybenzophenone (BP-3), and 2-(2-benzotriazol-2-yl)-4-methylphenol (UV-P). Large variabilities in usage of these chemicals resulted in different compositional patterns among the car seats. These results suggest that these compounds are major polymeric additives in children's car seats as they are present at greater levels than previously measured groups of chemicals like brominated flame retardants and per- and polyfluoroalkyl substances. Given the documented toxic potentials of synthetic antioxidants and ultraviolet filters, their abundances in children products are a cause for concern.

Occupant Injury and Response on Oblique-Facing Aircraft Seats: A Computational Study.

Increased interest in the airline industry to enhance occupant comfort and maximize seating density has prompted the design and installation of obliquely mounted seats in aircraft. Previous oblique whole-body sled tests demonstrated multiple failures, chiefly distraction-associated spinal injuries under oblique impacts. The present computational study was performed with the rationale to examine how oblique loading induces component level responses and associated injury occurrence. The age-specific human body model (HBM) was simulated for two oblique seating conditions (with and without an armrest). The boundary conditions consisted of a 16 g standard aviation crash pulse, 45 deg seat orientation, and with restrained pelvis and lower extremities. The overall biofidelity rating for both conditions ranged from 0.5 to 0.7. The validated models were then used to investigate the influence of pulse intensity and seat orientation by varying the pulse from 16 g to 8 g and seat orientation from 0 deg to 90 deg. A total of 12 parametric simulations were performed. The pulse intensity simulations suggest that the HBM could tolerate 11.2 g without lumbar spine failure, while the possibility of cervical spine failure reduced with the pulse magnitude <9.6 g pulse. The seat orientation study demonstrated that for all seat angles the HBM predicted failure in the cervical and lumbar regions at 16 g; however, the contribution of the tensile load and lateral and flexion moments varied with respect to the change in seat angle. These preliminary outcomes are anticipated to assist in formulating safety standards and in designing countermeasures for oblique seating configurations.

Elevated concentrations of halogenated flame retardants in waste childcare articles from Ireland.

Concentrations of legacy and alternative halogenated flame retardants (HFRs) including chlorinated organophosphate esters (Cl-OPEs), were measured in waste childcare articles (n = 275 for Cl-OPEs, n = 187 for other HFRs) from the Republic of Ireland between 2019 and 2020. Articles studied comprised foams and fabrics from: child car seats, cot mattresses, changing mats, pushchairs, prams, and related items. Fifteen articles (7.7%) exceeded the European Union limit value of 1000 mg/kg for polybrominated diphenyl ethers (PBDEs) (all due to BDE-209), an additional 15 exceeded the limit for hexabromocyclododecane (HBCDD), with 7 articles exceeding the limit for both PBDEs and HBCDD. An even greater proportion of articles contained concentrations exceeding 1000 mg/kg for: tris(1-chloro-2-propyl) phosphate (TCIPP) (n = 73, 27%) and tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) (n = 58, 21%), with concentrations greater than 1000 mg/kg also observed for: tris(2-chloroethyl) phosphate (TCEP) (n = 14, 5.1% articles), 2-ethylhexyl tetrabromobenzoate (EH-TBB) (n = 7, 3.7%), decabromodiphenyl ethane (DBDPE), and bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP) (both n = 5, 2.7%). Overall, 120 samples contained at least one HFR at a concentration exceeding 1000 mg/kg. In addition to the waste management implications of our findings, our data raise concerns about child exposure to HFRs during the use phase of these everyday items.

Changes in Pediatricians' Child Passenger Safety Counseling With Initiation of a Booster Seat Program.

Booster seats reduce injury in motor vehicle crashes, yet they are used less frequently than car seats and seat belts. Primary care providers are well positioned to educate and encourage families to use booster seats. We aimed to assess how a booster seat distribution program affected the documentation of restraint usage and anticipatory guidance at well-child visits at a pediatric primary care practice. We performed a retrospective chart review of patients aged 4 to 12 years from June to December in 2019 and 2020, representing before and after a booster seat program. The most frequently documented restraints in 2019 and 2020 were seat belts (51% vs 30%), booster seats (25% vs 27%), and not documented/unclear (17% vs 25%) (P < .001). The program significantly increased referrals for booster seats (P < .001). Despite significant differences in the proportion of children in each restraint category, overall booster seat use was similar between years.

The Effectiveness of Neutral Electrolyzed Water for Decontaminating the Spray Nozzles of Electric Tankless and Tank-Type Warm-Water Bidet Toilet Seats.

Electrolyzed water is a novel disinfectant that is widely used in the food industry. We conducted an experimental model-based study to determine the effectiveness of neutral electrolyzed water (NEW) for the daily nozzle cleaning of artificially contaminated tankless and tank-type bidet toilet seats. The toilet seats were designed to automatically self-clean the spray nozzles using tap water or NEW after each use or at specified intervals. The numbers of Pseudomonas aeruginosa and Escherichia coli microorganisms in the spray water were measured twice or thrice per week. A Kruskal-Wallis test was used to compare the bacterial count in the spray water of various cleaning (NEW) and control (tap water) conditions. The number of bacteria was significantly lower in NEW conditions with and without periodic nozzle cleaning functions than in tap water conditions for both tank-type and tankless bidet toilet seats. Microorganisms were detected only on the surface area around the opening for ejecting spray water and not in the internal piping at the spray nozzle tip. These findings demonstrate that NEW has superior decontamination efficacy over tap water when used as a cleaning agent for the spray nozzles of warm-water bidet toilet seats.

Analysis of 6YO pediatric human body model kinematics and kinetics to determine submarining across naturalistic seating postures.

OBJECTIVES: The aim of this study was to analyze the kinematics and kinetics of a naturalistically seated 6-year-old (6YO) pediatric human body model and evaluate the metrics described by earlier studies for pediatric ATDs to indicate whether different postures and booster seats were more associated with submarining than others in a frontal impact. METHODS: The PIPER 6YO pediatric human body model was restrained on a lowback (LBB) and a highback (HBB) booster child restraint seat (CRS) in four naturalistic seating postures: leaning-forward, leaning-inboard, leaning-outboard, and a pre-submarining posture, and a baseline reference seating position as per the FMVSS No. 213 protocol. A 2012 mid-size sedan finite element (FE) model was used as the vehicle environment. A standard 3-point lap-shoulder belt system was modeled to restrain the child and the CRS in the left-rear vehicle seat. Additionally, a No-CRS condition was modeled in a reference posture and pre-submarining posture in which the occupant's legs bent over the edge of the rear seat. 12 conditions were simulated in LS-DYNA R10.1.0, and kinematics and kinetics were compared to metrics as per prior literature: 1) maximum femur displacement and pelvis rotation, 2) maximum knee-head excursion and maximum change in torso angle, 3) lap belt trajectory relative to pelvis's coordinate frame. RESULTS: The pre-submarining posture on the HBB depicted submarining in all metrics except for the lap belt trajectory. Only the pre-submarining posture in No-CRS depicted submarining through analysis of all metrics. For this pre-submarining No-CRS condition, the mid-abdominal compression was approximately 5 times greater than the average of the mid abdominal compression depths of all other cases and maximum abdominal pressure was at least 22.9 kPa higher than the rest of the conditions. CONCLUSIONS: The results of this study suggest that metrics used to assess submarining for 6YO pediatric occupants in frontal impacts may need to be updated so that they are more accurate for both simulated and physical studies. In addition, the results of this study could be used to design booster seats that discourage postures that could lead to an increased likelihood of submarining-like characteristics in a frontal crash impact.

Restraint Use for Child Occupants in Dubai, United Arab Emirates.

The overall objective of the current study was to investigate the behaviours and knowledge of parents/carers in relation to safe child occupant travel in the Emirate of Dubai in the United Arab Emirates (UAE). A community survey was completed by 786 participants who were responsible for the safety of 1614 children (aged 10 years and younger). The survey included questions related to the type, frequency and appropriateness of restraint use for their eldest child. Overall, 24 percent of participants reported that they 'never/almost never' restrained their eldest child while travelling in a motor vehicle, with this proportion increasing with child age. For example, though 89 percent of participants reported that they restrained their infants (<1 year) in an 'appropriate' restraint for their age, this rate was much lower for children aged between 5 and 7 years (10%). Overall, these findings suggest that a large proportion of child occupants, especially those aged five years and older, are not appropriately restrained in vehicles, and therefore are at an increased risk of death or serious injury in the event of a crash. Future research will validate this self-reported child restraint use data with objective data from observations of real-world child restraint use behaviour in the UAE.

Give Me A Boost: A Child Passenger Safety Educational Intervention.

BACKGROUND: Motor vehicle crashes (MVCs) are a leading cause of morbidity and mortality among children, yet belt-positioning booster seats remain underutilized. This study analyzed the impact of a provider-oriented child passenger safety (CPS) educational intervention on pediatric resident confidence, knowledge, and counseling behavior in the primary care setting. METHODS: Pre- and post-educational intervention cross- sectional surveys were distributed to pediatric residents focusing on confidence, knowledge, barriers to, and frequency of CPS discussions. RESULTS: Pre-intervention, only 16% (95% CI: 6.2-32%) of respondents reported confidence in their knowledge of the American Academy of Pediatrics' (AAP) booster seat recommendations. Post-intervention frequency of CPS discussion, confidence and knowledge in all measured aspects increased. CONCLUSIONS: While pediatric residents are well positioned for CPS counseling, they lack adequate baseline knowledge of CPS recommendations, particularly for booster seats. Brief educational interventions can increase and maintain provider knowledge and confidence in counseling families on appropriate child car safety seats.

Rear-seat seatbelt use in urban Southeast Asia: results from Bandung and Bangkok.

Road traffic injuries (RTIs) remain a leading cause of morbidity and mortality in Southeast Asia. We aim to estimate the prevalence and predictors of rear seatbelt use, a key behavioural risk factor for RTI, in Bandung and Bangkok, two cities in Southeast Asia. Roadside observational studies were conducted to provide a representative picture of the prevalence in each city. From eight rounds of observations (July 2015 to April 2019), 39,479 and 7,207 rear-seat passengers were observed in Bandung and Bangkok. Across all rounds, 4.2% of rear-seat passengers used seatbelts in Bandung, compared to 8.4% in Bangkok. In both cities, males and adults, as compared to females and adolescents (aged 12-17 years), had higher odds of rear seatbelt use, as did passengers with a restrained driver. Findings highlight the need for rear seatbelt laws in Bandung and improved enforcement of existing rear seatbelt laws in Bangkok.

Seasonality in COVID-19 times.

COVID-19 hit the economy in an unprecedented way, changing the data generating process of many series. We compare different seasonal adjustment methods through simulations, introducing outliers in the trend and seasonality to reproduce the heterogeneity in the series during COVID-19.

Use of child safety seats and booster seats in the United States: A comparison of parent/caregiver-reported and observed use estimates.

BACKGROUND: Motor-vehicles crashes are a leading cause of death among children. Age- and size-appropriate restraint use can prevent crash injuries and deaths among children. Strategies to increase child restraint use should be informed by reliable estimates of restraint use practices. OBJECTIVE: Compare parent/caregiver-reported and observed child restraint use estimates from the FallStyles and Estilos surveys with the National Survey of the Use of Booster Seats (NSUBS). METHODS: Estimates of child restraint use from two online, cross-sectional surveys-FallStyles, a survey of U.S. adults, and Estilos, a survey of U.S. Hispanic adults-were compared with observed data collected in NSUBS. Parents/caregivers of children aged ≤ 12 years were asked about the child's restraint use behaviors in FallStyles and Estilos, while restraint use was observed in NSUBS. Age-appropriate restraint use was defined as rear-facing child safety seat (CSS) use for children aged 0-4 years, forward-facing CSS use for children aged 2-7 years, booster seat use for children aged 5-12 years, and seat belt use for children aged 9-12 years. Age-appropriate restraint users are described by demographic characteristics and seat row, with weighted prevalence and corresponding 95% confidence intervals (CI) calculated. RESULTS: Overall, child restraint use as reported by parents/caregivers was 90.8% (CI: 87.5-94.1) (FallStyles) and 89.4% (CI: 85.5-93.4) for observed use (NSUBS). Among Hispanic children, reported restraint use was 82.6% (CI: 73.9-91.3) (Estilos) and 84.4% (CI: 79.0-88.6) for observed use (NSUBS, Hispanic children only). For age-appropriate restraint use, estimates ranged from 74.3% (CI: 69.7-79.0) (FallStyles) to 59.7% (CI: 55.0-64.4) (NSUBS), and for Hispanic children, from 71.5% (CI: 62.1-81.0) (Estilos) to 57.2% (CI: 51.2-63.2) (NSUBS, Hispanic children only). Conclusion and Practical Application: Overall estimates of parent/caregiver-reported and observed child restraint use were similar. However, for age-appropriate restraint use, reported use was higher than observed use for most age groups.