The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Jeremy Broughton - One of the best experts on this subject based on the ideXlab platform.
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The actual threat posed by unrestrained Rear Seat car passengers.
Accident; analysis and prevention, 2004Co-Authors: Jeremy BroughtonAbstract:A statistical analysis of the threat posed by unrestrained Rear Seat car passengers to restrained drivers and front Seat passengers was published in 2002. This was based on Japanese accident data from 1995 to 1999, and the conclusions have been checked using corresponding accident data from Great Britain. The law in respect of the use of Seat belts and other restraint systems was less strict in Japan than in Great Britain between 1995 and 1999, so an earlier period had to be studied. The results suggest that the risk of death to a front Seat car occupant is increased by about three-quarters by the presence of an unrestrained Rear Seat passenger behind them, a much smaller increase than was claimed by the Japanese researchers.
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THE THREAT POSED BY UNRESTRAINED Rear Seat CAR PASSENGERS
2003Co-Authors: Jeremy BroughtonAbstract:A Rear Seat car passenger who is not restrained by a Seat belt or other restraint system can be thrown forward in an accident and kill or injure the restrained driver or passenger ahead of them. A recent analysis of Japanese accident data has estimated that the risk of death to front Seat occupants is increased five-fold by the presence of an unrestrained Rear Seat passenger, and that the increase is even greater in frontal impacts. This report reviews the analysis and concludes that its results are not reliable, principally because of a serious deficiency in the number of fatalities among the data studied. It analyses British casualty data and data from the TRL Seat Belt Survey and concludes that the risk is increased by about three-quarters: it appears that between 8 and 15 front Seat occupants die each year in this country as a result of an unrestrained passenger Seated behind them. (A)
Jeffrey Richard Crandall - One of the best experts on this subject based on the ideXlab platform.
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Epidemiology of injuries sustained by Rear-Seat passengers in frontal motor vehicle crashes
Journal of Transport & Health, 2017Co-Authors: Dipan Bose, Jeffrey Richard Crandall, Jason Forman, Douglas Longhitano, Carlos Arregui-dalmasesAbstract:Abstract Objective Advanced occupant protection systems in motor-vehicles (e.g., Seat belts and airbags), while widely adopted for front-Seat passengers, are either absent or offer disproportionally lower safety to Rear-Seat passengers in similar crashes. Optimization of advanced restraint systems for the Rear-Seat environment will require a detailed understanding of epidemiology and associated risk factors for injuries sustained by Rear-Seat passengers. Thus, the objective of the study is to use national level motor-vehicle travel and crash data to quantify Rear-Seat travel exposure, and determine the descriptive characteristics and the injury outcomes for Rear-Seat passengers involved in frontal collisions. Methods While U.S. travel data from the 2009 National Household Travel Survey was used to determine Rear-Seat travel estimates, crash data from 2001 to 2010 National Automotive Sampling System Crash Worthiness Data System was used to enroll Rear-Seat passengers injured in a frontal crash. The descriptive epidemiology of Rear-Seat crash victims was separately done for the three age-groups: children (8–15 years old), adults (16–59 years old), and senior adults (60+). Results The study indicated that senior adults in Rear-Seats were associated with a significantly higher rate of sustaining fatal (6%) and severe injuries (16% for MAIS 3+ injuries) in comparison to the younger cohorts. The distribution of severe injuries further indicated that the thorax was the most frequently injured region across all age groups irrespective of the belt-use status. Conclusions Findings of the study conclude that while Rear-Seat travel in the U.S. is still very low and improving belt usage is a primary concern among Rear-Seat passengers; however, the epidemiology supports the need for adapting Rear-Seat restraint performance for effective protection for all groups of Rear-Seat passengers.
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Increased risk of driver fatality due to unrestrained Rear-Seat passengers in severe frontal crashes.
Accident; analysis and prevention, 2013Co-Authors: Dipan Bose, Carlos Arregui-dalmases, David Sanchez-molina, Juan Velazquez-ameijide, Jeffrey Richard CrandallAbstract:While belt usage among Rear-Seat passengers is disproportionately lower than their front-Seat counterpart, this may have serious consequences in the event of a crash not only for the unbelted Rear-Seat passenger but also for the front-Seat passengers as well. To quantify that effect, the objective of the study is to evaluate the increased likelihood of driver fatality in the presence of unrestrained Rear-Seat passengers in a severe frontal collision. U.S.-based census data from 2001 to 2009 fatal motor vehicle crashes was used to enroll frontal crashes which involved 1998 or later year vehicle models with belted drivers and at least one adult passenger in the Rear left Seat behind the driver. Results using multivariate logistic regression analysis indicated that the odds of a belt restrained driver sustaining a fatal injury was 137% (95% CI = 95%, 189%) higher when the passenger behind the driver was unbelted in comparison to a belted case while the effects of driver age, sex, speed limit, vehicle body type, airbag deployment and driver ejection were controlled in the model. The likelihood of driver fatality due to an unrestrained Rear left passenger increased further (119–197%) in the presence of additional unrestrained Rear Seat passengers in the Rear middle or right Seats. The results from the study highlight the fact that future advances to front row passive safety systems (e.g. multi-stage airbag deployment) must be adapted to take into account the effect of unrestrained Rear-Seat passengers.
Dipan Bose - One of the best experts on this subject based on the ideXlab platform.
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Epidemiology of injuries sustained by Rear-Seat passengers in frontal motor vehicle crashes
Journal of Transport & Health, 2017Co-Authors: Dipan Bose, Jeffrey Richard Crandall, Jason Forman, Douglas Longhitano, Carlos Arregui-dalmasesAbstract:Abstract Objective Advanced occupant protection systems in motor-vehicles (e.g., Seat belts and airbags), while widely adopted for front-Seat passengers, are either absent or offer disproportionally lower safety to Rear-Seat passengers in similar crashes. Optimization of advanced restraint systems for the Rear-Seat environment will require a detailed understanding of epidemiology and associated risk factors for injuries sustained by Rear-Seat passengers. Thus, the objective of the study is to use national level motor-vehicle travel and crash data to quantify Rear-Seat travel exposure, and determine the descriptive characteristics and the injury outcomes for Rear-Seat passengers involved in frontal collisions. Methods While U.S. travel data from the 2009 National Household Travel Survey was used to determine Rear-Seat travel estimates, crash data from 2001 to 2010 National Automotive Sampling System Crash Worthiness Data System was used to enroll Rear-Seat passengers injured in a frontal crash. The descriptive epidemiology of Rear-Seat crash victims was separately done for the three age-groups: children (8–15 years old), adults (16–59 years old), and senior adults (60+). Results The study indicated that senior adults in Rear-Seats were associated with a significantly higher rate of sustaining fatal (6%) and severe injuries (16% for MAIS 3+ injuries) in comparison to the younger cohorts. The distribution of severe injuries further indicated that the thorax was the most frequently injured region across all age groups irrespective of the belt-use status. Conclusions Findings of the study conclude that while Rear-Seat travel in the U.S. is still very low and improving belt usage is a primary concern among Rear-Seat passengers; however, the epidemiology supports the need for adapting Rear-Seat restraint performance for effective protection for all groups of Rear-Seat passengers.
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Increased risk of driver fatality due to unrestrained Rear-Seat passengers in severe frontal crashes.
Accident; analysis and prevention, 2013Co-Authors: Dipan Bose, Carlos Arregui-dalmases, David Sanchez-molina, Juan Velazquez-ameijide, Jeffrey Richard CrandallAbstract:While belt usage among Rear-Seat passengers is disproportionately lower than their front-Seat counterpart, this may have serious consequences in the event of a crash not only for the unbelted Rear-Seat passenger but also for the front-Seat passengers as well. To quantify that effect, the objective of the study is to evaluate the increased likelihood of driver fatality in the presence of unrestrained Rear-Seat passengers in a severe frontal collision. U.S.-based census data from 2001 to 2009 fatal motor vehicle crashes was used to enroll frontal crashes which involved 1998 or later year vehicle models with belted drivers and at least one adult passenger in the Rear left Seat behind the driver. Results using multivariate logistic regression analysis indicated that the odds of a belt restrained driver sustaining a fatal injury was 137% (95% CI = 95%, 189%) higher when the passenger behind the driver was unbelted in comparison to a belted case while the effects of driver age, sex, speed limit, vehicle body type, airbag deployment and driver ejection were controlled in the model. The likelihood of driver fatality due to an unrestrained Rear left passenger increased further (119–197%) in the presence of additional unrestrained Rear Seat passengers in the Rear middle or right Seats. The results from the study highlight the fact that future advances to front row passive safety systems (e.g. multi-stage airbag deployment) must be adapted to take into account the effect of unrestrained Rear-Seat passengers.
Richard W. Kent - One of the best experts on this subject based on the ideXlab platform.
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Rear Seat occupant safety an investigation of a progressive force limiting pretensioning 3 point belt system using adult pmhs in frontal sled tests
Stapp car crash journal, 2009Co-Authors: Jason Forman, Richard W. Kent, Francisco J Lopezvaldes, David Lessley, Matthew W Kindig, Stephen A Ridella, Ola BoströmAbstract:This paper will discuss how Rear Seat adult occupant protection is receiving increased attention from the automotive safety community. Recent anthropomorphic test device (ATD) studies have suggested that it may be possible to improve kinematics and reduce injuries to Rear Seat occupants in frontal collisions by incorporating shoulder-belt force-limiting and pretensioning (FL+PT) technologies into Rear Seat 3-point belt restraints. This study seeks to further investigate the feasibility and potential kinematic benefits of a FL+PT Rear Seat, 3-point belt restraint system in a series of 48 kmh frontal impact sled tests (20 g, 80 ms sled acceleration pulse) performed with post mortem human surrogates (PMHS). Three PMHS were tested with a 3-point belt restraint with a progressive (two-stage) force limiting and pretensioning retractor in a sled buck representing the Rear Seat occupant environment of a 2004 mid-sized sedan. Instrumentation included belt tension load cells, accelerometers on the head and at multiple locations on the spine, and chestbands to measure the chest deformation contours in the transverse plane. The kinematics of the subjects were quantified using off-board, high-speed video. The results of these tests were then compared to matched PMHS tests, published in 2008, performed in the same environment with a standard (not-force limited, not pretensioning) 3-point belt restraint. The FL+PT restraint system resulted in significant (p\ml0.05) decreases in peak shoulder belt tension (average \mP standard deviation: 4.4 \mP 0.13 kN with the FL+PT belt, 7.8 \mP 0. 6 kN with the standard belt) and 3 ms-resultant, mid-spine acceleration (FL+PT: 34 \mP 3.8 g; standard belt: 44 \mP 1.4 g). The FL+PT tests also produced more forward torso rotation caused by decreased forward excursion of the pelvis and increased payout out of the shoulder belt by the force-limiter. These results support the previous ATD studies that suggest that it may be possible to improve the kinematics of Rear Seat occupants in this type of collision using a 3-point belt system with a shoulder belt retractor equipped with a two-stage force-limiter and pretensioner.
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Rear-Seat motor vehicle travel in the U.S.: Using national data to define a population at risk
American journal of preventive medicine, 2009Co-Authors: Matthew J. Trowbridge, Richard W. KentAbstract:Background Recent studies suggest that the relative protection offered by Rear Seating in motor vehicle crashes has decreased, potentially reflecting disproportionate advancements in front-Seat safety technology. Safe adaptation of advanced front-Seat restraint systems for the Rear-Seat environment will require exposure data that are currently unavailable. Purpose This study uses national data to quantify Rear-Seat occupancy patterns, restraint use, and annual travel exposure in the U.S. in order to support the development of advanced crash protection systems for Rear-Seat motor vehicle occupants. Methods Data from the 2000–2006 National Automotive Sampling System Crashworthiness Data System and 2001 National Household Transportation Survey were analyzed in 2008 to quantify occupancy patterns (e.g., Seat position, restraint use) and annual person-trips for Rear-Seat passengers in the U.S. Results The overall proportion of person-trips by Rear-Seat occupants is relatively low (12.9%); however national at-risk exposure remains significant (approximately 39 billion annual person-trips). Annual Rear-Seat travel exposure is similar among children ≤12 years and adults (18.9 vs 19.1 billion person-trips) despite the fact that children are proportionally much more likely to ride in Rear positions (79.3% vs 7.4%). Restraint use among adult Rear-Seat occupants was also much lower than among front-Seat occupants (50.4% vs 82.2%). Conclusions While Rear-Seat occupancy is relatively low compared with front-Seat occupancy at-risk Rear-Seat travel by both child and adult passengers in the U.S. remains significant. Restraint use by Rear-Seat occupants is much lower than that among front-Seat passengers, particularly among adults and older children, substantially increasing injury risk. Development of future crash protection systems for Rear-Seat passengers must account for these exposure patterns to ensure safe and effective integration into production vehicles.
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occupant restraint in the Rear Seat atd responses to standard and pre tensioning force limiting belt restraints
Annals of advances in automotive medicine Annual Scientific Conference ... Association for the Advancement of Automotive Medicine. Association for the, 2008Co-Authors: Jason Forman, Shashi Kuppa, Richard W. Kent, Jarett Michaelson, Ola BoströmAbstract:This paper describes how recent studies have shown that restrained occupants over the age of 50 in frontal crashes have a higher risk of injury in the Rear Seat than in the front, and these studies have hypothesized that the incorporation of technology such as belt pre-tensioning and force limiting preferentially in the front Seat is at least partially responsible for this trend. This paper investigates the potential benefits and trade-offs of Seat belt pretensioners and force-limiters in the Rear Seat using a series of frontal impact sled tests at two speeds (48 km/h and 29 km/h DeltaV) with a buck representing the interior of the reat Seat occupant compartment of a contemporary mid-sized sedan. Four different dummies were tested: the Hybrid III six year old (in a booster Seat, H3 6YO), the Hybrid III 5(th) percentile female (H3 AF05), the Hybrid III 50(th) percentile male (H3 AM50), and the THOR-NT. The restraints consisted of either a standard three point belt, or a 3-point belt with a retractor pretensioner and a progressive force-limiter (FL+PT). Each test condition was repeated in triplicate. The FL+PT restraints (compared to the standard restraints) resulted in a significant (p < or = 0.05) decrease in peak internal chest deflection for each of the Hybrid III dummies at both test speeds (48 km/h: 29% decrease for H3 6YO, 38% decrease for H3 AF05, 30% decrease for H3 AM50), and for the THOR-NT at a DeltaV of 29 km/h. At 48 km/h, the FL+PT restraint qualitatively decreased the average peak internal chest deflection of the THOR-NT, however this decrease was not statistically significant (p=0.06). Furthermore, the FL+PT system allowed little or no increase in forward head excursion, and improved whole-body kinematics for all dummies by restricting pelvic excursion and slightly increasing torso pitch. The results suggest that the FL+PT system studied here may provide injury-reducing benefit to Rear Seat occupants in moderate to high severity frontal crashes, although more study is needed to evaluate these restraints in other crash scenarios.
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Rear Seat Occupant Protection in Frontal Crashes and Its Feasibility
2007Co-Authors: Richard W. Kent, Jason Forman, Daniel P Parent, Shashi KuppaAbstract:As part of the National Highway Traffic Safety Administration's (NHTSA's) Rear Seat Occupant Protection Research Program, the Fatality Analysis Reporting System (FARS) and State Data System (SDS) for Florida, Pennsylvania and Maryland were utilized to estimate relative fatality rates and injury risk ratios between the front and Rear Seat passengers. In addition, a parametric study of Rear-Seat restraint parameters was performed to assess chest deflection and head excursion trends for different belt load limits, pretensioner location(s) and stroke, and impact speeds with the Hybrid III (HIII) 50th percentile male and 5th percentile female dummies. Simulation data were validated using 48 km/h frontal impact sled tests with a standard belt system in outboard Rear Seats of a mid-size passenger car buck. The real world data suggests that the fatality and serious injury risk in frontal crashes is higher for older occupants in Rear Seats than for those in front Seats. In addition, the relative effectiveness (to mitigate serious injury and death) of Rear Seats with respect to front Seats for restrained adult occupants in newer vehicle models is less than it is in older models, presumably due to the advances in restraint technology that have been incorporated into the front Seat position. The simulations demonstrated that adult dummy injury measures in the Rear Seat can be reduced by incorporating restraint technology (load limiting and pretensioning) used in the front Seat, even in the absence of an air bag and knee bolster for load sharing. A force-limiting belt with a pretensioner in the Rear Seat can maintain or reduce head excursion relative to a standard belt, while significantly reducing chest deformation and thoracic injury risk. In fact, 42 sets of restraint parameters were identified that reduced both head excursion and chest deflection of the 50th percentile male relative to the baseline belt.
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The feasibility and effectiveness of belt pretensioning and load limiting for adults in the Rear Seat
International Journal of Vehicle Safety, 2007Co-Authors: Richard W. Kent, Jason Forman, Daniel P Parent, Shashi KuppaAbstract:The US Fatality Analysis Reporting System (FARS) and State Data System (SDS) for Florida, Pennsylvania and Maryland were utilised to estimate relative fatality rates and injury risk ratios between the front and Rear-Seat passengers, and a parametric study of Rear-Seat restraint parameters was performed to assess chest deflection and head excursion trends. The fatality and serious injury risk in frontal crashes is found to be higher for older occupants in Rear Seats than for those in front Seats. In addition, the relative effectiveness of Rear Seats is lower in newer vehicle models, presumably due to the advances in front-Seat restraint technology. The simulations demonstrate that injury risk in the Rear Seat can be reduced by incorporating front-Seat restraint technology (load limiting and pretensioning), even in the absence of an air bag and knee bolster. A force-limiting belt with a pretensioner can maintain or reduce head excursion relative to a standard belt, while reducing thoracic injury risk. In fact, 42 sets of restraint parameters were identified that reduced both head excursion and chest deflection relative to the baseline belt.
Dennis R Durbin - One of the best experts on this subject based on the ideXlab platform.
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Rear Seat safety variation in protection by occupant crash and vehicle characteristics
Accident Analysis & Prevention, 2015Co-Authors: Jessica S. Jermakian, Dennis R Durbin, Michael J Kallan, Anne Taylor Mccartt, Kristy B Arbogast, Mark R Zonfrillo, Rachel K MyersAbstract:Abstract Objectives Current information on the safety of Rear row occupants of all ages is needed to inform further advances in Rear Seat restraint system design and testing. The objectives of this study were to describe characteristics of occupants in the front and Rear rows of model year 2000 and newer vehicles involved in crashes and determine the risk of serious injury for restrained crash-involved Rear row occupants and the relative risk of fatal injury for restrained Rear row vs. front passenger Seat occupants by age group, impact direction, and vehicle model year. Method Data from the National Automotive Sampling System Crashworthiness Data System (NASS-CDS) and Fatality Analysis Reporting System (FARS) were queried for all crashes during 2007–2012 involving model year 2000 and newer passenger vehicles. Data from NASS-CDS were used to describe characteristics of occupants in the front and Rear rows and to determine the risk of serious injury (AIS 3+) for restrained Rear row occupants by occupant age, vehicle model year, and impact direction. Using a combined data set containing data on fatalities from FARS and estimates of the total population of occupants in crashes from NASS-CDS, logistic regression modeling was used to compute the relative risk (RR) of death for restrained occupants in the Rear vs. front passenger Seat by occupant age, impact direction, and vehicle model year. Results Among all vehicle occupants in tow-away crashes during 2007–2012, 12.3% were in the Rear row where the overall risk of serious injury was 1.3%. Among restrained Rear row occupants, the risk of serious injury varied by occupant age, with older adults at the highest risk of serious injury (2.9%); by impact direction, with rollover crashes associated with the highest risk (1.5%); and by vehicle model year, with model year 2007 and newer vehicles having the lowest risk of serious injury (0.3%). Relative risk of death was lower for restrained children up to age 8 in the Rear compared with passengers in the right front Seat (RR = 0.27, 95% CI 0.12–0.58 for 0–3 years, RR = 0.55, 95% CI 0.30–0.98 for 4–8 years) but was higher for restrained 9–12-year-old children (RR = 1.83, 95% CI 1.18–2.84). There was no evidence for a difference in risk of death in the Rear vs. front Seat for occupants ages 13-54, but there was some evidence for an increased relative risk of death for adults age 55 and older in the Rear vs. passengers in the right front Seat (RR = 1.41, 95% CI 0.94–2.13), though we could not exclude the possibility of no difference. After controlling for occupant age and gender, the relative risk of death for restrained Rear row occupants was significantly higher than that of front Seat occupants in model year 2007 and newer vehicles and significantly higher in Rear and right side impact crashes. Conclusions Results of this study extend prior research on the relative safety of the Rear Seat compared with the front by examining a more contemporary fleet of vehicles. The Rear row is primarily occupied by children and adolescents, but the variable relative risk of death in the Rear compared with the front Seat for occupants of different age groups highlights the challenges in providing optimal protection to a wide range of Rear Seat occupants. Findings of an elevated risk of death for Rear row occupants, as compared with front row passengers, in the newest model year vehicles provides further evidence that Rear Seat safety is not keeping pace with advances in the front Seat.
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Association Between NCAP Ratings and Real-World Rear Seat Occupant Risk of Injury.
Traffic injury prevention, 2015Co-Authors: Kristina B Metzger, Siobhan Gruschow, Dennis R Durbin, Allison E CurryAbstract:Several studies have evaluated the correlation between U.S. or Euro New Car Assessment Program (NCAP) ratings and injury risk to front Seat occupants, in particular driver injuries. Conversely, little is known about whether NCAP 5-star ratings predict real-world risk of injury to restrained Rear Seat occupants. The NHTSA has identified Rear Seat occupant protection as a specific area under consideration for improvements to its NCAP. In order to inform NHTSA's efforts, we examined how NCAP's current 5-star rating system predicts risk of moderate or greater injury among restrained Rear Seat occupants in real-world crashes. We identified crash-involved vehicles, model year 2004-2013, in NASS-CDS (2003-2012) with known make and model and nonmissing occupant information. We manually matched these vehicles to their NCAP star ratings using data on make, model, model year, body type, and other identifying information. The resultant linked NASS-CDS and NCAP database was analyzed to examine associations between vehicle ratings and Rear Seat occupant injury risk; risk to front Seat occupants was also estimated for comparison. Data were limited to restrained occupants and occupant injuries were defined as any injury with a maximum Abbreviated Injury Scale (AIS) score of 2 or greater. We linked 95% of vehicles in NASS-CDS to a specific vehicle in NCAP. The 18,218 vehicles represented an estimated 6 million vehicles with over 9 million occupants. Rear Seat passengers accounted for 12.4% of restrained occupants. The risk of injury in all crashes for restrained Rear Seat occupants was lower in vehicles with a 5-star driver rating in frontal impact tests (1.4%) than with 4 or fewer stars (2.6%, P =.015); results were similar for the frontal impact passenger rating (1.3% vs. 2.4%, P =.024). Conversely, side impact driver and passenger crash tests were not associated with Rear Seat occupant injury risk (driver test: 1.7% for 5-star vs. 1.8% for 1-4 stars; passenger test: 1.6% for 5 stars vs 1.8% for 1-4 stars). Current frontal impact test procedures provide some degree of discrimination in real-world Rear Seat injury risk among vehicles with 5 compared to fewer than 5 stars. However, there is no evidence that vehicles with a 5-star side impact passenger rating, which is the only crash test procedure to include an anthropomorphic test dummy (ATD) in the Rear, demonstrate lower risks of injury in the Rear than vehicles with fewer than 5 stars. These results support prioritizing modifications to the NCAP program that specifically evaluate Rear Seat injury risk to restrained occupants of all ages.
