Front Seat Passengers Research Articles

Warning signs to fasten seat belts result in higher rates of rear seat belt use in rideshare vehicles

Using seat belts reduces traffic injuries and fatalities. Passengers in the rear seat typically use their seat belts less often than drivers or front-seat passengers. Seat belt use in the back is even less frequent in vehicles for hire such as taxi cabs and rideshare vehicles than in private passenger vehicles. This observational study of adult passengers video-recorded in rideshare vehicles in San Francisco found that a sign mounted at rear passenger seated eye level, and that warned of the risks of failing to wear a seat belt, resulted in significantly higher rates of seat belt use than for rear seat passengers not exposed to the warning sign. Results also showed that age, gender, and trip duration did not have a significant effect on rear seat belt use. Implications for future research and other countermeasures are discussed.

Impaired driving: A case report. Pickup truck centerline crossover collision with medium-size bus on U.S. Highway 83, Concan, Texas, United States

Objective: The objective of this communication is to describe a crash involving an impaired pickup truck driver who crossed the centerline and struck a medium-size bus carrying senior adults restrained with lap-only belts that resulted in 13 fatalities.Methods: Document review of the National Transportation Safety Board investigation was performed. Documents are available at: https://dms.ntsb.gov/pubdms/search/hitlist.cfm?docketID=61581&CFID=2452299&CFTOKEN=9e7f5cd49ac23dc3-47A7BE1A-B81A-1A8F-7B1554A90617B722.Results: Prior to the crash, the erratic movement of the pickup truck being driven by a 20-year-old man was videotaped by witnesses in a following vehicle (https://www.youtube.com/watch?v=jsGsbYTwWbM). The 14.5-min cell phone recording demonstrated the pickup truck swerving repeatedly over the double yellow center line and onto the shoulder. The recording ended before the crash. While rounding a curve in the roadway, the pickup crossed the centerline and struck a medium-size bus with 14 occupants. All but one of the rearmost bus occupants were fatally injured in the collision. The pickup driver survived with serious injuries. Following the crash, toxicology testing found that the pickup truck driver had used marijuana in combination with a prescription benzodiazepine, clonazepam. The bus occupants ranged in age from 64 to 87 years old and all were wearing the available restraints, which included lap–shoulder belts and air bags (both of which deployed) for the driver and front seat passenger. Of the 12 rear passenger seats, 8 were equipped with traveling retractor lap belt assemblies and the 2-person bench seats in the last row on each side of the bus were equipped with manually adjustable lap belt assemblies.Conclusions: The failure of the truck driver to maintain control of his vehicle was due to impairment stemming from his use of marijuana in combination with misuse of a prescribed medication, clonazepam. Following the crash, the pickup driver was sentenced to 55 years in prison. Improved countermeasures including guidance and access to improved roadside testing methods, expanded law enforcement training to detect impaired drivers, enhanced enforcement regarding impairment by combinations of drugs or drugs and alcohol, as well an evaluation and implementation of data-driven strategies are needed to reduce fatalities, injuries, and crashes involving drivers impaired by alcohol and other drugs. The lap belts provided insufficient protection for the passengers seated in the rear of the bus aft of the intrusion zone; standard installation by vehicle manufacturers of lap–shoulder belts on medium-size as well as larger buses (now required) could mitigate the risk of injury in the event of a crash.

Factors associated with chest injuries to front seat occupants in frontal impacts

Objective: Frontal impact chest protection in European cars has been highlighted as an area where possible improvements could be made. The chest is particularly vulnerable in older occupants whose numbers are forecast to increase significantly in the coming decades. This study aimed to provide some direction to areas for possible improvements in frontal crash chest protection.Methods: Real-world crash injury data were interrogated, focusing on cars with current restraint components. The research examined belted front seat occupants in frontal impacts where airbags, pretensioners, and load limiters were present.Results: The chest was the most often injured body region at Abbreviated Injury Scale (AIS) 2+, 3+, and 4+ injury levels. The rate of AIS 2+ and AIS 3+ chest injuries was highest among elderly occupants and lowest among young occupants, and elderly occupants sustained proportionally more severe chest injuries in low/moderate-speed impacts compared to young and middle-aged occupants. However, it should be noted that rates of AIS 2 chest injury were also significantly higher for middle-aged occupants compared to the young. The front passenger seat was shown to be more often associated with significant chest injury than the driver seat. The higher proportion of elderly female occupants was postulated as a reason for this. Skeletal injury was the most frequent type of AIS 2+ chest injury, and the rate of injury for elderly occupants with such injuries was higher than that for young and middle-aged occupants. With the increase in the number of rib fractures, the risk of pulmonary complications and organ injuries tended to increase. The major cause of chest injury was identified as restraining loads transmitted to the chest via the seat belt. The absence of intrusion in the majority of cases suggests an opportunity for the restraint system to better manage the crash pulse, not only for elderly occupants but for those who are middle-aged as well.Conclusions: This study shows the necessity for safety interventions, through new vehicle crashworthiness systems, to improve chest protection, especially for middle-aged and elderly car occupants. Deployment of appropriate injury risk criteria, use of an appropriate dummy thorax, development of a low-energy restraint test, and the development of more adaptive restraints have been discussed as possible solutions to the problem.

A comparison of seat belt fit and comfort experience between older adults and younger front seat passengers in cars

Objective: The purpose was to study how occupant age affects seat belt fit and comfort by comparing older adults and younger occupants in the front seat of a passenger vehicle.Methods: An exploratory user study was performed for the front seat of a stationary large passenger vehicle in a laboratory environment, including 11 older (aged 72–81) and 11 younger (aged 25–30) participants. Each participant first entered the vehicle and buckled up in a predefined seat position. Next, they adjusted the seat to their preferred seat position and buckled up again. Anthropometric data were collected on height, weight, and waist and hip circumferences. Photographs and measurements were taken of seat/seat belt positions and posture, and structured interviews were conducted regarding comfort perceptions of the 2 tested scenarios, including previous experience and awareness of seat belt usage and discomfort experienced as passengers in cars.Results: Nonoptimal belt fit included shoulder belt on the shoulder edge or close to the neck or lap belt over the abdomen. Five of 11 older adults had nonoptimal belt fit in the predefined position, and in the preferred position 7 older adults had nonoptimal belt fit. Only one showed safety awareness and recognized the nonoptimal belt fit in the preferred position. In the younger group, 4 of 11 had nonoptimal belt fit in the predefined position and 4 in the preferred position. Two acknowledged the nonoptimal belt fit. Older adult participants with a more pronounced kyphotic posture had the upper part of the shoulder belt positioned closer to the suprasternal notch compared to younger participants. Older adults were also more likely to have the lower part of the shoulder belt higher up on the abdomen compared to younger participants. Participants with higher body mass indexes (BMIs) were more likely to have the shoulder belt higher up on the abdomen, independent of age and gender. When the shoulder belt was positioned higher up on the abdomen the upper portion of the shoulder belt was routed closer to the throat. Older adults preferred to sit higher up to achieve a better field of vision compared to younger adults.Conclusions: The change in body posture due to aging influences belt fit. Older adults seemed less aware of safety related to belt fit. Increased BMI influenced shoulder belt fit, independent of age. These findings are important when designing restraint systems to ensure safety for all occupants.

Motion sickness in passenger vehicles during test track operations

As automation transforms drivers into passengers, the deployment of automated vehicles (AVs) has the potential to greatly increase the incidence of motion sickness. A study was conducted to quantify motion sickness response of front-seat passengers performing ecologically relevant passenger activities during conditions consistent with driving on public roadways. Fifty-two adults with a large range of self-reported levels of motion sickness susceptibility and age participated in data collection on a closed test track in a passenger sedan. Motion sickness ratings increased with task vs. no-task and moderate vs. low acceleration test conditions. Increased motion sickness susceptibility was associated with higher motion sickness ratings. In comparison to older participants (age > 60), younger participants (age < 60) experienced increased motion sickness. This is the first in-vehicle study that systematically compared normative passenger activities and acceleration magnitudes typical of normative driving conditions on motion sickness response for a large, diverse sample of passengers, enabling the exploration of the effects of covariates. Practitioner summary: The data demonstrate that a relatively large range of motion sickness response can be expected to result from passengers performing visual tasks in passenger vehicles. Measurement and modelling efforts should seek to elucidate relationships among the factors contributing to motion sickness for the purpose of informing and prioritising future countermeasures for automated vehicles (AVs). Abbreviations: AV(S): automated vehicles; BMI: body mass index; BVP: blood volume pulse; EDA: electrodermal activity; FMS: fast motion sickness scale; GPS: global positioning system; IMU: inertial measurement unit; ISO: International Organization for Standardization; MISC: misery scale; MSDV: motion sickness dose value; NDS: naturalistic driving study; SAE: Society of Automotive Engineers International; UMTRI: The University of Michigan Transportation Research Institute Key Aspect of Research: Motion sickness may be an important barrier to widespread adoption of automated vehicles @UMTRI.

An in-depth technical and medical investigation of facial injuries caused by car accidents

BackgroundMany studies have investigated the issue of facial injuries caused by car accidents, but only a few have addressed the technical and clinical aspects of such accidents and injuries in depth. The aim of this study was to identify risk factors and protective elements for facial injuries in car accidents. MethodsWe analysed the technical and clinical data of patients with facial injuries caused by car accidents over a 16-year period (2000–2016) and investigated the following factors: sitting position, sex, age, accident time, use of a seatbelt, deployment of the front airbag, direction of impact, speed at the time of collision, and occurrence and location of facial injuries. ResultsOf the 1291 patients involved in car accidents who were included in our study, 291 (22.5%) had suffered facial injuries. We found a significant association between occurrence of facial injuries and sex, speed at the time of collision, impact from the back, seatbelt usage, and deployment of the front airbag. In accidents occurring at speeds over 40 km/h, automobile security measures had no significant influence on the occurrence of facial injuries in drivers and front-seat passengers. In accidents occurring at speeds between 0 and 20 km/h, seatbelt usage (without airbag deployment) solely showed a significant protective influence against the occurrence of facial injuries (odd ratio [OR], 0.130; confidence interval [CI], 0.038–0.451). In contrast, patients who were in accidents at speeds between 21 and 40 km/h suffered significantly fewer facial injuries when wearing a seatbelt with the front airbag being deployed (OR, 0.245; CI, 0.091–0.665) or undeployed (OR, 0.216; CI, 0.084–0.561). ConclusionMale sex and a high speed at the time of collision are significant risk factors for the occurrence of facial injuries. The security measurements evaluated in this study only exerted a protective influence at low speeds (below 40 km/h). This indicates a possible weakness of these security systems with regard to preventing facial injuries. Engineers could benefit from these findings and improve the efficiency of existing security measures and eventually help decrease the incidence of facial injuries.

Nighttime seat belt use among front seat passengers: Does the driver's belt use matter?

Introduction and Method: We explored the relationship between nighttime seat belt use of right-front passengers and their drivers using observational data from 33,310 vehicles in east Tennessee during March 2015 – May 2017. Results: Overall, nighttime passenger seat belt use varied by 50 percentage points from 92% when drivers were belted to 42% when drivers were not belted, suggesting that part-time seat belt users can be heavily influenced by the seat belt status of their traveling companions. When stratified by vehicle type and sex, passenger seat belt use by driver seat belt status varied as much as 74 percentage points from 96% to 22%. Passenger seat belt use was typically lower when riding with unbelted same-sex drivers than when riding with unbelted drivers of the opposite sex. Conclusions and Practical Applications: This finding suggests that the role of peer influence in decision-making about seat belt use may differ depending on the sex of a vehicle driver and his or her passengers. Further research is warranted to explore this finding as well as other social and cultural influences that have not been fully examined in seat belt research.

Effective Factors of Seat-Belt Use in front Seat Passenger on Urban Trips of Bushehr: Application of Protection Motivation Theory

Effective Factors of Seat-Belt Use in front Seat Passenger on Urban Trips of Bushehr: Application of Protection Motivation Theory

Pattern Recognition: A Mechanism-based Approach to Injury Detection after Motor Vehicle Collisions

Motor vehicle collisions cause substantial mortality, morbidity, and expense worldwide. Certain types of injuries are more likely to result from frontal versus side-impact collisions, and knowledge of these specific patterns and why they occur aids in accurate and efficient diagnosis of traumatic injuries. Although the proper use of seat belts decreases crash-related mortality during frontal impact, certain injury patterns to the torso are directly attributed to restraint use. The spectrum of seat belt-related injuries ranges from mild skin and soft-tissue contusions to traumatic bowel injuries and unstable spine injuries that require surgery. Impact with the steering wheel or windshield during a frontal crash can cause characteristic injuries to the head, neck, torso, and distal upper extremity. Steering wheel deformity is an independent predictor of serious thoracic and abdominal injury among front-seat passengers. Impact of a flexed knee with the dashboard during a frontal collision can cause knee, thigh, and hip injuries. Distal lower extremity injuries are encountered frequently when the floorboard is driven into the foot. Lateral impact crashes often result in traumatic brain, thoracic, abdominal, and pelvic injuries, which are more often fatal to occupants on the side of the impact. The specific mechanism-based injury patterns are reviewed to establish a structured systematic search pattern that enables the radiologist to identify traumatic injuries with greater accuracy and speed, thereby improving the care of patients who experience acute trauma. ©RSNA, 2019 See discussion on this article by Ballard and Mellnick .

The influence of certain factors on the specific features of the injuries inflicted to the children involved in the motor vehicle traffic accidents

The objective of the present study was to elucidate the influence of the age of the child, its location in the passenger compartment of the vehicle, and the application of the safety seat belts on the frequency of the injuries inflicted to the children involved in the motor vehicle traffic accidents. The analysis of the relevant clinical materials has demonstrated the non-uniform influence of the factors being evaluated on the specific features of the injuries to the different parts of the children's body. The age of the child was found to have the most pronounced effect on the character of the injuries. Direct correlation was documented between the age and the frequency and severity of the injuries to the body and bone of the lower legs whereas the frequency and severity of the fractures of the femoral bones as well as of the craniocerebral traumas showed inverse correlation with the age. The bones of the upper arm and the forearm are most frequently fractured in the 3-6-year-old children. The location of the child in the passenger compartment at the moment of the accident also influences the character of the injury. The front seat passengers most frequently suffer the severe injuries to the head and the fractures of the lower extremities. The injuries to the body and the fractures of the upper extremities occur more frequently in the children occupying the back seats. Fixation of the children with the safety belts is an important factor having the influence on the frequency and severity of the injuries caused to the body and the lower extremities in the children in the passenger compartment of a car. The absence of fixation increases the occurrence of injuries to the internal organs of the chest and abdominal cavities and of the fractures of the thoracic and pelvic bones. Moreover, the frequency of fractures of the femoral, mid- and lower leg bones increases.

Road traffic injuries measures in the Eastern Mediterranean Region: findings from the Global Status Report on Road Safety - 2015.

:Background:The Eastern Mediterranean Region has the second highest road traffic fatality rate in the world. This article presents the epidemiology of road traffic injuries and the preventive measures in Eastern Mediterranean Region taken by the different World Health Organization member states compared to the rest of the world.Methods:This is a secondary data analysis addressing the Global Status Report on Road Safety published by the World Health Organization in 2015. Data are from 180 countries covering 6.97 billion people of the world’s population, of which 21 Eastern Mediterranean Region of World Health Organization member states with about 595 million population were included and were analyzed. From 22 countries in the region, 21 are presented and Syria has not reported any data on road traffic injuries.Results:Eastern Mediterranean Region member states contribute to 9.69% of all global fatal road traffic injuries (19.9 per 100 000 population compared to the same rate in the European region with 9.3), while these countries account for 7.4% of the world’s population and have about 5.6% of the world’s vehicles on their roads. More than 90% of the Eastern Mediterranean Region countries have passed mandatory seat-belt laws for both front-seat and rear-seat passengers and making helmet use obligatory; and only 27% have child restraint laws; half percent have an emergency room injury surveillance system. All countries have a national drink-driving law; and certain speed limits but there is no distinction between rural and urban areas, and the latter lack adequate speed restrictions.Conclusions:Although the Eastern Mediterranean Region member states have some important preventive measures recommended by World Health Organization, considerable efforts are still needed to optimize the enforcement of existing road safety laws. The maximum urban speed limit should be reduced in many countries. Sufficient attention should be paid to the needs of pedestrians, cyclists and motorcyclists, who together make up about 50% of Eastern Mediterranean Region road traffic deaths.

Evaluating Seat Belt Use in Lebanon (1997-2017)

Introduction:The use of seat belts has made a significant contribution to the reduction of road traffic casualties, and the risk inherent with not wearing seat belts in all seats of a vehicle is now well-known worldwide. The use of seat belts has a major role in reducing fatal and nonfatal injuries in all types of motor-vehicles crashes.Aim:The aim of this study is to understand the reasons behind the variation in seat belt use over the past two decades in Lebanon. It analyzes the situation and suggests recommendations to improve seat belt use in Lebanon.Design:Nine observational studies had been conducted in Lebanon during the last two decades between 1997 and 2017, and one qualitative study was performed in 2017.Results:The results show a significant variation in the use of the seat belt. When enforcement efforts are in progress, seat belt use increases. While when there are no checkpoints and the enforcement of seat belt use is almost absent, a significant fall was noticed.Discussion:The results of this study proved the failure of the Lebanese government in saving hundreds of lives just by a simple measure of enforcing seat belt law. Although experiences from various countries prove that such laws usually have a long-lasting effect on seat belt use, Lebanon failed to pursue the successful implementation of this law due to security and political problems.Conclusion:During the past two decades, Lebanon witnessed continuous fluctuations in seat belt use. Outside few short enforcement campaigns, our observations showed lack in seat belt use. Our observations of seat belt use among drivers and front seat passengers showed a significant correlation between seat belt use and the enforcement of seat belt law.The greatest national benefits from seat belt use are obtained when wearing rates are very high. This can be achieved only through a sustained enforcement campaign alongside other seat belt wearing interventions such as publicity and education.

Effect of car speed on the transmission of vibration through the seat pan and backrest: field study

This study investigates the effect of car speed on the vibration transmitted to the passenger through both the seat pan and backrest. Ten male subjects sat in the front passenger seat of a sedan car and were driven at three different speeds (60, 80 and 100 km/h). During each ride, the vibration dose value (VDV) was measured in the x, y and z-directions on the seat pan and at the backrest. The results showed an increase in the VDV in all directions with increasing the car speed. The VDVs at the backrest were found as high as, or even higher than, those measured on the seat depending on the speed and the measurement axis. Hence, it is recommended that vibration in road vehicles be assessed using more than one speed while taking into consideration measurement at the backrest.

Effect of car speed on the transmission of vibration through the seat pan and backrest: field study

This study investigates the effect of car speed on the vibration transmitted to the passenger through both the seat pan and backrest. Ten male subjects sat in the front passenger seat of a sedan car and were driven at three different speeds (60, 80 and 100 km/h). During each ride, the vibration dose value (VDV) was measured in the x, y and z-directions on the seat pan and at the backrest. The results showed an increase in the VDV in all directions with increasing the car speed. The VDVs at the backrest were found as high as, or even higher than, those measured on the seat depending on the speed and the measurement axis. Hence, it is recommended that vibration in road vehicles be assessed using more than one speed while taking into consideration measurement at the backrest.

Neck muscle responses of driver and front seat passenger during frontal-oblique collisions.

BackgroundLow-velocity motor vehicle crashes often lead to severe and chronic neck disorders also referred to as whiplash-associated disorders (WAD). The etiology of WAD is still not fully understood. Many studies using a real or simulated collision scenario have focused on rear-end collisions, whereas the kinematics and muscular responses during frontal-oblique collisions have hardly been investigated. In particular for rear-end collisions, drivers were shown to have a higher WAD risk than front seat passengers. Yet, independently from the impact direction, neither the muscular nor the kinematic responses of drivers and front seat passengers have been compared to date, although some findings indicate that the neck muscles have the potential to alter the head and neck kinematics, and that the level of neck muscle activity during impact may be relevant for the emergence of WAD.ObjectiveIn this study, we quantitatively examined the subjects’ neck muscle activity during low-velocity left-frontal-oblique impacts to gain further insights into the neuromuscular mechanism underlying whiplash-like perturbations that may lead to WAD.MethodsIn a within-subject study design, we varied several impact parameters to investigate their effect on neck muscle response amplitude and delay. Fifty-two subjects experienced at least ten collisions while controlling for the following parameters: change in velocity Δv (3 / 6 km/h), seating position (driver / front seat passenger), and deliberate pre-tension of the musculature (tense / relaxed) to account for a potential difference between an expected and an unexpected crash. Ten of the 52 subjects additionally ran the same experimental conditions as above, but without wearing a safety belt.FindingsThere were significant main effects of Δv and muscle pre-tension on the reflex amplitude but not of seating position. As for the reflex delay, there was a significant main effect of muscle pre-tension, but neither of Δv nor of seating position. Moreover, neither the safety belt nor its asymmetrical orientation had an influence on the reflexive responses of the occupants.ConclusionIn summary, we did not find any significant differences in the reflex amplitude and delay of the neck musculature between drivers and front seat passengers. We therefore concluded that an increased risk of the driver sustaining WAD in frontal-oblique collisions, if it exists, cannot be due to differences in the reflexive responses.

Belief about seat belt use and seat belt wearing behavior among front and rear seat passengers in the United States

Introduction: Unrestrained drivers and passengers represent almost half of all passenger vehicle occupant deaths in the United States. The current study assessed the relationship between the belief about importance of seat belt use and the behavior of always wearing a seat belt. Method: Data from 2012 ConsumerStyles were analyzed separately for front and rear passenger seating positions. Multivariable regression models were constructed to identify the association between seat belt belief and behavior (i.e., always wears seat belt) among adults. Models controlled for type of state seat belt law (primary, secondary, or none). Results: Seat belt use was higher in front passenger seats (86.1%) than in rear passenger seats (61.6%). Similarly, belief that seat belt use was very important was higher in reference to the front passenger seat (84.2%) versus the rear passenger seat (70.5%). For the front passenger seat, belief was significantly associated with seat belt use in states with both primary enforcement laws (adjPR 1.64) and secondary enforcement laws (adjPR 2.77). For the rear passenger seat, belief was also significantly associated with seat belt use, and two 2-way interactions were observed (belief by sex, belief by region). Conclusions: Despite overall high rates of seat belt use in the United States, certain groups are less likely to buckle up than others. The study findings suggest that efforts to increase seat belt use among high-risk populations, such as those who live in states with secondary or no seat belt laws and those who ride in rear seats (which include people who utilize taxis or ride-hailing vehicles) could benefit from interventions designed to strengthen beliefs related to the benefits of seat belt use. Practical applications: Future research that uses a theoretical framework to better understand the relationship between beliefs and behavior may inform interventions to improve seat belt use.

Passenger head kinematics in abrupt braking and lane change events

Objective: A test track study was conducted to quantify patterns of adult front seat passenger head motion during abrupt vehicle maneuvers.Method: Eighty-seven men and women with a wide range of body sizes and ages participated in data collection on a closed test track in a passenger sedan under manual control by a test driver. Because a primary goal of the study was to gather “unaware” data, the participants were instructed that the study was concerned with vehicle dynamics and they were required to read from a questionnaire taped to the top of their thighs as the drive began. The first event was a hard brake (approximately 1 g) to a stop from 35 mph (56 kph). Within the space of approximately 5 min the participants also experienced an aggressive lane change, a sharp right turn with simultaneous hard braking, and a second hard braking event. A Microsoft Kinect v2 sensor was positioned to view the area around the front passenger seat. Head location was tracked using the Kinect data with a novel methodology that fit 3D head scan data to the depth data acquired in the vehicle.Result: The mean (standard deviation) forward excursion of the estimated head center of gravity (CG) location in the first braking event was 135 (62) mm. The forward head CG excursion in the second braking event of 115 (51) mm was significantly less than that in the first, but the difference was small relative to the within-condition variance. Head excursion on the second braking trial was less than that on the first trial for 69% of participants. The mean maximum inboard head excursion in lane-change maneuvers was 118 (40) mm. Forward head excursions in braking were significantly smaller for older passengers and those with higher body mass index, but the combined factors accounted for less than 25% of the variance. Inboard head excursion in the lane-change event was significantly related to stature, but only about 7% of variance was related to body size. Head excursions for men and women did not differ significantly after accounting for body size.Discussion: This is the first quantitative occupant dynamics study to use a large, diverse sample of passengers, enabling the exploration of the effects of covariates such as age and body size.Conclusions: The data demonstrate that a relatively large range of head positions can be expected to result from abrupt vehicle maneuvers. The data do not support simple scaling of excursions based on body size.

Trends in the use of seat belts and mobile phones and their seasonal variations in Florence (2005-2015).

IntroductionAbout 1.25 million people worldwide die every year because of road accidents. Risk is higher when drivers use mobile phones, whereas seat belts help to prevent crash-related injury. We aimed to evaluate the prevalence, associated factors, and temporal trend of the use of seat belts and mobile phones among drivers and passengers in Florence, Italy (2005–2015).MethodsUse of seat belts and mobile phones use was monitored via direct observation in four areas in the province of Florence. We fitted Poisson regression models with robust variance to investigate the factors associated with the use of seat belts and mobile phones use by the drivers and to explore long-term trends and seasonal patterns in the two time-series.ResultsWe observed a total of an overall 134,775 vehicles: seat belts were worn by 71.8% of drivers and front-seat passengers and 27.6% of back-seat passengers, while mobile phones were being used by 4.8% of drivers. Drivers were more likely to wear seat belt when transporting passengers (≥2 vs none: prevalence ratio [PR] 1.21, 95% confidence intervals [CI] 1.14–1.29) and while driving in the afternoon (PR 1.04, 95% CI 1.03–1.05), and less likely when the front-seat passenger was not wearing seat belts (PR 0.33, 95% CI 0.32–0.34). After an initial increase, seat belts use by the driver decreased over time (-0.5% each year during 2010–2015), with significant peaks and troughs in July and January, respectively. Mobile phone use by the driver was inversely associated with wearing seat belts (PR 0.67, 95% CI 0.64–0.70) and carrying passengers (≥2 vs. none PR 0.20, 95% CI 0.07–0.52). The proportion of drivers using mobile phones did not vary over time nor showed any clear seasonality.ConclusionsDrivers’ risky behaviours (not wearing a seat belt and using a mobile phone) are associated, showing a global misperception of risk among a subset of drivers. The number of passengers and their behaviour is also associated with the driver’s attitude. The effectiveness of primary enforcement laws has declined in Italy in recent years; therefore, other strategies should be devised and implemented.

Current use of safety restraint systems and front seats in Korean children based on the 2008-2015 Korea National Health and Nutrition Examination Survey.

Purpose The use of proper safety restraint systems by children is vital for the reduction of traffic accident-related injury and death. This study evaluated the rates of use of safety restraint systems and front seats by Korean children.Methods Based on data from the National Health and Nutrition Examination Survey from 2008 to 2015, I investigated the frequencies of safety restraint systems and front seat use by children under six and 12 years of age, respectively.Results The percentage of respondents who said they always use safety restraint systems increased from 17.7% in 2008 to 45.0% in 2015. The rate of children who did not use the front seats at all was 47.3 % in 2008 compared to 33.4% in 2015. Multivariate logistic regression analysis showed a decrease in safety-restraint-system use as age increased (odds ratio, 0.63; 95% confidence interval [CI], 0.51–0.77). The use rate of front-passenger seat belts by the mother is significantly correlated with the safety-restraint- system use rate by children (odds ratio, 2.14; 95% CI, 1.12–4.06).Conclusion Although the rate of safety-restraint-system use for children is increasing annually, it remains low. Additionally, the use rate of front passenger seats for children is high. To reduce the rates of injury and death of children from traffic accidents, it is necessary to educate on the appropriate use of safety restraint systems according to age and body size and to develop stronger regulations.

Head postures during naturalistic driving

Objective: A rotated head posture at the time of a rear-end impact is associated with a higher risk of acute and chronic whiplash injury. The objective of this study was to quantify the amplitude and duration of rotated head postures observed in drivers during naturalistic driving.Methods: Twenty volunteers (14 males: 36 ± 12 years, 6 females: 27 ± 5 years) drove a 2010 Subaru Impreza on public roads while their 3D head angular position relative to the car was recorded using inertial measurement units. An experimenter rode in the passenger seat (right side) and logged when subjects performed one of 6 head movements: Bilateral shoulder and side mirror checks, looking at the rearview mirror, and looking at the front seat passenger. Video of the subjects was used to confirm the logged head movements and identify movements that the experimenter missed. The duration and amplitude of all 6 head movements were tabulated and then compared between periods when the car was moving and when the car was stationary.Results: During a 68 ± 5-min drive, subjects performed a median (range) of 15 (5–39) left shoulder checks, 82.5 (29–167) left mirror checks, 40.5 (10–168) rearview mirror checks, 27.5 (3–113) right mirror checks, 60 (0–185) passenger looks, and 12.5 (1–28) right shoulder checks. Peak yaw angles of the head relative to the vehicle for these 6 movements averaged −81.5°, −34.3°, 16.2°, 42.1°, 58.2°, and 84.3°, respectively. Drivers spent a larger proportion of time in nonneutral postures when the vehicle was stopped (17.5%) compared to moving (8.2%) (Z = 3.92, P < .0001). Drivers also moved their head further from neutral during the movements when the car was stationary compared to moving (t19 = 5.90, P < .0001).Conclusions: Drivers use larger and longer duration head movements when stationary than when driving. Given an increased risk of whiplash injury for initially rotated head postures, these findings provide a possible explanation for why drivers are more likely to be injured when hit from behind while their vehicle is stationary. Further, the head postures characterized in this study can be used as initial conditions in volunteer and computational studies to improve our understanding of why nonneutral head postures are associated with increased whiplash injury risk.