Standard Seat Belt Research Articles

Analysis of Head Displacement during a Frontal Collision at a Speed of 20 km/h—Experimental Studies

The aim of the research is to compare the head displacements of volunteers with the head displacements of the KPSIT C50 dummy, taking into account the change of vehicle seat belts. Unfortunately, sudden braking or collisions between vehicles is becoming more and more common, especially during traffic jams. There is considerable ignorance in the literature on the behavior of the human body during a low-speed collision, which motivates the development of low-speed crash test procedures in order to reduce the risk of cervical spine injuries. The tests were carried out at a teaching station designed to measure the forces in seat belts and the displacements of individual body elements (dummy or volunteer) during a low-speed crash test. The article is part of extensive research on crash tests using volunteers and KPSIT physical dummies. The study involved 150 volunteers who were divided into specific percentile groups. The article compares the head displacements of the constructed KPSIT C50 dummy with the head displacements of volunteers representing the 50th percentile group of the male population. The study conducted with volunteers was under control and was completely safe for people participating in the study. The research shows that the use of a bucket sports seat equipped with four-point or five-point seat belts significantly reduces the movement of the head during a low-speed collision. This type of vehicle seat is safer and provides a reduced risk of injury from hitting the head on the steering column in a low-speed collision when the airbag has not deployed. Moreover, research shows that standard seat belts placed in passenger vehicles allow the head to move freely forward in the event of an accident or low-speed collision. Therefore, if the speed is too low to deploy the airbag, there is a high probability that the driver and passengers will hit their heads against the cockpit of the passenger vehicle during a collision at a speed of 20 km/h.

50 percentile dummy movement analysis using TEMA Automotive software

The dynamic loads acting on passengers during road accidents depend not only on the vehicle structure, but also on the properties of the applied passenger and driver protection system. Two-point seat belts are the most frequently used personal protection system for adult passengers in bus vehicles. The paper investigates the thread of dynamic loads acting on the body of a 50 percentile dummy placed in an armchair equipped with two-point seat belts. In order to solve this problem, tests recorded with the Phantom v310 camera were used, the object of which was the Hybrid II 50th dummy, and the recording of the tests was carried out for three different collision speeds. The article presents the results of the crash tests obtained with the use of the TEMA Automotive program. Crash test analysis showing the displacement of the head and upper torso of the dummy located in the limited space between the bus-type seats indicates that standard seat belts do not provide sufficient protection. The article indicates the basis for further research and improvement of the personal protection system of passengers transported in minibuses and buses.

Frontal collision simulation in laboratory conditions

The article presents the displacement of individual body parts of volunteers during a controlled crash test at low speed. The crash test stand used is equipped with a vehicle seat with standard seat belts, which moves along the ramp rails. The stand enables both front, side and rear crash tests. The stand enables crash tests from 5 km/h to 20 km/h. The aim of the research is to compare the displacements of individual parts of the volunteers’ body, taking into account the division into sex. A study carried out on 130 volunteers (80 men and 50 women), at a collision speed of 15 km/h, showed slight differences in the trajectory of the volunteers’ head movement. Before the study, the volunteers were measured and weighed, and then assigned to the appropriate population percentile. Volunteers were classified into a given percentile group on the basis of the mean of 15 anthropometric dimensions of individual body parts. The obtained results are the basis for building a physical model of a dummy.

Selection of child seats in terms of vibration comfort

The article presents the results of laboratory and road tests of the impact of the method of fastening child seats on the vibration comfort of children transported in them. The tested child seats were mounted facing the direction of travel on the rear seat of a passenger vehicle. Two child seats were used in the work, the first (red) was attached to the rear seat behind the driver’s seat using the ISOFIX base. The second child seat (grey) is attached to the rear seat behind the passenger seat with standard seat belts. During the measurements, the child seats were loaded with the mass of 5 kg, 10 kg and 15 kg, simulating the mass of a child fastened in a child seat. The child seats used can be mounted both forward and rearward facing. In the conducted research, they were installed in a passenger vehicle facing the direction of travel. Laboratory and road tests based on registered vertical accelerations showed a negative impact of using the ISOFIX base in terms of vibration comfort.

Research and Analysis of the Propagation of Vertical Vibrations in the Arrangement of a Vehicle Seat-A Child's Seat.

This paper deals with the issues of the impact of vertical vibrations on a child seated in a child seat during a journey. Its purpose was to assess the impact of fastening the child seats and road conditions on the level of vibrations recorded on child seats. The paper describes the tested child seats, the methodology of the tests and the test apparatus included in the measuring track. The tests were carried out in real road conditions where the child seats were located on the rear seat of a passenger vehicle. One was attached with standard seat belts, and the other with the ISOFIX base. When driving on roads with three types of surface, the following vertical accelerations were measured: seat of the child seats, the rear seat of the vehicle and the ISOfix base. The recorded accelerations were first analyzed in the time domain and then in the frequency domain. Three indexes (r.m.s, rmq and VDV) were used to assess the vibration comfort. Research has shown that the classic method of fastening a child seat with standard seat belts is more advantageous in terms of vibration comfort. Calculated indicators confirmed the negative impact of separating the child seat from the rear seat of the vehicle using the IQ ISOFIX base.

Forensic assessment of seat belt injuries caused to a minor passenger in the rear seat

The purpose of this work is to draw attention to the problem of child injuries in road traffic accidents. Children are the most vulnerable road users. Seat belts as elements of passive safety of cars cannot always provide the necessary protection. In some cases, they act as traumatic objects. A case of a thoracic spine injury (fractures of the bodies of two thoracic vertebrae) in a minor child who was on a booster and fixed with a standard seat belt is presented. The data of clinical and special research methods are presented, as well as options for solving some forensic issues are considered.

Numerical analysis of passenger kinematics and injury risks during a railway vehicle collision: The effect of safety belts

The aim of this paper is to contribute to investigation of passive safety of passengers in railway vehicles using numerical simulations. At first, a typical interior of a railway vehicle is created in the Virtual Performance Solution software. It includes finite element models of seats. Their mechanical properties have been determined experimentally. Particular attention is paid to the table in the backseat as a potentially harmful element. In numerical simulations, both folded and unfolded states of the table are considered. The passenger is represented with the virtual human body model Virthuman. Its structure is composed of rigid bodies and deformable segments to account for deformability of soft tissues. It allows for the prediction of injury risk. The numerical simulations aim to investigate the potential benefit of standard seat belts in a railway vehicle. Therefore, the passenger is seated considering three configurations: seating with no constraints, belted with a two-point belt and a three-point belt. The interior is loaded with a crash-pulse prescribed by the GM/RT2100 regulation. The results are discussed in terms of passenger kinematics and injury risk.

Estimating the Effect of Standard Enforcement of a Rear Seat Belt Law for Rear Seat Fatality Prevention

Data were collected from the NHTSA’s Fatality Analysis Reporting System to analyze the link between primary enforcement of rear seat belt use and injury severity in fatal vehicle collisions. Specifically, this study predicted the amount of fatalities that may have been prevented had there been standard enforcement of a rear seat belt law in effect. Previous literature concludes that increasing seat belt use will decrease injury severity in collisions and the primary enforcement of seat belts laws will increase seat belt use by approximately 14%. This study recorded and compared the number of rear seat fatalities in states that did and did not have primary enforcement laws for rear seat occupants. The results indicated that, on average, for every properly restrained rear seat fatality there are 0.45 more rear seat fatalities in states without primary enforcement than states with primary enforcement. It also predicts that the states that do not practice standard seat belt enforcement could have seen approximately 772 to 1,032 fatalities prevented from 2011 to 2015, had there been primary rear seat belt enforcement. This corresponds to an estimated national crash cost savings of $8.6 billion, or $1.7 billion annually.

Booster Seats and Traffic Fatalities Among Children

In an effort to increase booster seat use among children, the National Highway Traffic Safety Administration is encouraging state legislators to promote stricter booster seat laws, yet there is a paucity of information on booster seat efficacy relative to other forms of restraint. Using data from the Fatality Analysis Reporting System for the period 2008-2014 and the sample selection correction proposed by Levitt and Porter (2001), the current study examines the effectiveness of booster seats relative to child safety seats and adult seat belts. For children 6 to 8 years of age, we find that booster seats are more than twice as effective as child safety seats and over 30 percent more effective than standard seat belts at decreasing the likelihood of fatality in a motor vehicle accident. For children 2 to 5 years of age, all three forms of restraint appear equally effective.

Successful Scientific Replication and Extension of Levitt (2008): Child Seats are Still No Safer Than Seat Belts

SummaryUsing US fatality data from 1975 to 2003, Levitt (Evidence that seat belts are as effective as child safety seats in preventing death for children aged two and up, Review of Economics and Statistics 2008; 90(1): 158–163) shows that child safety seats do not significantly reduce fatalities for children aged 2–6 years as compared to standard seat belts. Although we were unable to gain access to the original programs and dataset used, we were able to replicate Levitt's () findings almost exactly. We extend Levitt () by showing that the findings also hold for the years 2004–2011 despite changing driver characteristics and restraint use patterns. We fail to find evidence that SUVs provide additional safety for children. Copyright © 2015 John Wiley & Sons, Ltd.

A Human Body Model With Active Muscles for Simulation of Pretensioned Restraints in Autonomous Braking Interventions

Objective: The aim of this work is to study driver and passenger kinematics in autonomous braking scenarios, with and without pretensioned seat belts, using a whole-body finite element (FE) human body model (HBM) with active muscles.Methods: Upper extremity musculature for elbow and shoulder flexion–extension feedback control was added to an HBM that was previously complemented with feedback controlled muscles for the trunk and neck. Controller gains were found using a radial basis function metamodel sampled by making 144 simulations of an 8 ms−2 volunteer sled test. The HBM kinematics, interaction forces, and muscle activations were validated using a second volunteer data set for the passenger and driver positions, with and without 170 N seat belt pretension, in 11 ms−2 autonomous braking deceleration. The HBM was then used for a parameter study in which seat belt pretension force and timing were varied from 170 to 570 N and from 0.25 s before to 0.15 s after deceleration onset, in an 11 ms−2 autonomous braking scenario.Results: The model validation showed that the forward displacements and interaction forces of the HBM correlated with those of corresponding volunteer tests. Muscle activations and head rotation angles were overestimated in the HBM when compared with volunteer data. With a standard seat belt in 11 ms−2 autonomous braking interventions, the HBM exhibited peak forward head displacements of 153 and 232 mm for the driver and passenger positions. When 570 N seat belt pretension was applied 0.15 s before deceleration onset, a reduction of peak head displacements to 60 and 75 mm was predicted.Conclusions: Driver and passenger responses to autonomous braking with standard and pretensioned restraints were successfully modeled in a whole-body FE HBM with feedback controlled active muscles. Variations of belt pretension force level and timing revealed that belt pretension 0.15 s before deceleration onset had the largest effect in reducing forward head and torso movement caused by the autonomous brake intervention. The displacement of the head relative to the torso for the HBM is quite constant for all variations in timing and belt force; it is the reduced torso displacements that lead to reduced forward head displacements.

Successful Scientific Replication and Extension of Levitt (2008): Child Seats are Still No Safer than Seat Belts

Using US fatality data from 1975 to 2003, Levitt (2008) shows that child safety seats do not significantly reduce fatalities for children aged two to six as compared to standard seat belts. Although we were unable to gain access to the original programs and dataset used, we were able to replicate Levitt's (2008) findings almost exactly. We extend Levitt (2008) by showing that the findings also hold for the years 2004 to 2011 despite changing driver characteristics and restraint use patterns. We fail to find evidence that SUVs provide additional safety for children.

CHILD SAFETY IN A CAR DURING A FRONTAL COLLISION

Road accidents with participation of the children are of particular nature. According to surveys, the older children at the age of 8-12 years are often transported in cars in a wrong way. They are usually fastened with seat belts designed for adult passengers. In order to make the seat belts safe for a child, they should be used together with a booster cushion or a high back booster seat. This paper presents the test results and analysis of dynamic loads affecting a child in the back seat of a passenger car during a frontal collision. The car body was accelerated to a speed of about 48 km/h and then it was suddenly stopped in a time of about 100 ms. The analysis was carried out on the basis of results of experimental tests performed at the collision station in the Automotive Industry Institute in Warsaw. The attention was paid to the influence of protection device type on the P10 dummy, representing a child at the age of about 10 years. Three child protection options during a collision were considered: the dummy was sitting directly in a car seat, on a booster cushion and on a seat. The dummy was fastened with standard seat belts. Evaluation of the protection device influence on the dummy loads was given in association with the operation of the seat belts. During evaluation, the indexes of biomechanical resistance of a human body to the impact load effects were used. They made the basis for the evaluation of the child injury severity risk.

Buckle up: non-seat belt use and antisocial behavior in the United States

ObjectiveTo compare persons who report that they never wear a seat belt while driving or as a passenger with those who do in a nationally representative sample in the United States. Our guiding hypothesis is that failure to wear a seat belt is part of an antisocial behavior spectrum. MethodsUsing public-use data from the 2010 National Survey on Drug Use and Health, this study employed binary logistic regression with adjustments for complex survey sampling to assess relationships between never wearing a seat belt and sociodemographic variables, antisocial behaviors, substance abuse and co-occurring problems, and criminal justice system contact. ResultsIndividuals who do not wear seat belts are younger, more likely to be male, less likely to be African American or Hispanic, have incomes of less than $75,000, and be a high school or college graduate. After controlling for the effects of age, gender, race, income, education, and population density, individuals reporting that they never wear a seat belt while driving or as a passenger are more likely to report using alcohol and drugs (adjusted odds, 1.61–2.56), committing antisocial behaviors including felony offenses (adjusted odds, 2.13–3.57), and possess a dual diagnosis (adjusted odds, 1.62–1.73). ConclusionsFindings indicate that non-seat belt use is convergent with a spectrum of serious antisocial behavior and comorbid psychological distress. Importantly, results suggest that standard seat belt use policies and campaigns may not be effective for non-seat belt using individuals and a targeted approach may be needed.

Seat Belt Designs to Protect Pregnant Vehicle Occupants

Various restraint systems to protect vehicle occupants in case of an accident have been specifically designed for pregnant women and the ideas are filed for patents. The concepts cover a wide range of designs; from ‘add-on’ to standard 3-point seat belt solutions to relatively complex mechatronics applications. Auxiliary tools and equipments to offer lap belt solutions constitute the majority of the reviewed patents. Designs also vary according to their working principles. Some designs exclusively focus on the lap belt part of the seat belt, whereas some others attempt to resolve the problem from a broader perspective, offering overall seat belt solutions with or without the use of standard seat belt. In this article around forty patented ideas on seat belt designs for pregnant women are reviewed, classified and presented, highlighting the working principles and inventors’ claims.

Seat Belt Designs to Protect Pregnant Vehicle Occupants

Various restraint systems to protect vehicle occupants in case of an accident have been specifically designed for pregnant women and the ideas are filed for patents. The concepts cover a wide range of designs; from ‘add-on’ to standard 3-point seat belt solutions to relatively complex mechatronics applications. Auxiliary tools and equipments to offer lap belt solutions constitute the majority of the reviewed patents. Designs also vary according to their working principles. Some designs exclusively focus on the lap belt part of the seat belt, whereas some others attempt to resolve the problem from a broader perspective, offering overall seat belt solutions with or without the use of standard seat belt. In this article around forty patented ideas on seat belt designs for pregnant women are reviewed, classified and presented, highlighting the working principles and inventors claims.

Are seat belt restraints as effective in school age children as in adults? A prospective crash study

Objective: To study effectiveness of seat belts for protecting school age children in road vehicle crashes.Design: Crash examinations by trained investigators.Setting: Ten Canadian university based crash investigation centres.Subjects: 470 children...

Nonsanction seat belt law enforcement: A modern day tale of two cities

This paper describes the implementation and evaluation of a nonsanction seat belt law enforcement program in two experimental communities of contrasting size in a state with a mandatory belt law. The main ingredients of the program were seat belt “salutes,” public information and education, and limited use of inexpensive economic incentives. Driver shoulder belt use data collected before, during, and after the experimental programs, compared to similar data collected in a comparison community, showed the approach to be effective. While standard seat belt enforcement activities without incentives have been shown to be effective, many police departments, especially in smaller communities, are reluctant to make wholesale increases in seat belt citations. Although requiring some additional level of manpower and resources, a nonsanction approach to seat belt law enforcement can provide an alternate way of increasing belt use in these communities.