Risk factors affecting the severity of traffic accidents at Shanghai river-crossing tunnel

Objective: With increasing traffic volume and urban development, increasing numbers of underground tunnels have been constructed to relieve conflict between strained land and heavy traffic. However, as more long tunnels are constructed, tunnel traffic safety is becoming increasingly serious. Thus, it is necessary to acquire their implications and impacts. This study examined 4,539 traffic accidents that have occurred in 14 Shanghai river-crossing tunnels for the period 2011–2012 and analyze the correlation between potential factors and accident injury severity.

Methods: An ordered logit model was developed to examine the correlation between potential factors and accident injury severity.

Results: Results show that increased injury severity is associated with male drivers, drivers aged 65 years or older, accident time from midnight to dawn, weekends, wet road surface, goods vehicles, 3 or more vehicles, 4 or more lanes, middle speed limits (50–79 km/h), zone 3, extra-long tunnels (over 3,000 m), and maximum longitudinal gradient.

Conclusions: This article aims to provide useful information for engineers to develop interventions and countermeasures to improve tunnel safety in China.     

Analyzing injury severity of bus passengers with different movements

Objective: Though public transport vehicles are rarely involved in mass casualty accidents, when they are, the number of injuries and fatalities is usually high due to the high passenger capacity. Of the few studies that have been conducted on bus safety, the majority focused on vehicle safety features, road environmental factors, as well as driver characteristics. Nevertheless, few studies have attempted to investigate the underlying risk factors related to bus occupants. This article presents an investigation aimed at identifying the risk factors affecting injury severity of bus passengers with different movements.

Method: Three different passenger movement types including standing, seated, and boarding/alighting were analyzed individually using classification and regression tree (CART) method based on publicly available accident database of Great Britain.

Results: According to the results of exploratory analyses, passenger age and vehicle maneuver are associated with passenger injury severity in all 3 types of accidents. Moreover, the variable “skidding and overturning” is associated with injury severity of seated passengers and driver age is correlated with injury severity of standing and boarding/alighting passengers.

Conclusions: The CART method shows its ability to identify and easily explain the complicated patterns affecting passenger injury severity. Several countermeasures to reduce bus passenger injury severity are recommended.     

Predictors of restraint use among child occupants

Objectives: The objective of this study was to identify factors that predict restraint use and optimal restraint use among children aged 0 to 13 years.

Methods: The data set is a national sample of police-reported crashes for years 2010–2014 in which type of child restraint is recorded. The data set was supplemented with demographic census data linked by driver ZIP code, as well as a score for the state child restraint law during the year of the crash relative to best practice recommendations for protecting child occupants. Analysis used linear regression techniques.

Results: The main predictor of unrestrained child occupants was the presence of an unrestrained driver. Among restrained children, children had 1.66 (95% confidence interval, 1.27, 2.17) times higher odds of using the recommended type of restraint system if the state law at the time of the crash included requirements based on best practice recommendations.

Conclusions: Children are more likely to ride in the recommended type of child restraint when their state's child restraint law includes wording that follows best practice recommendations for child occupant protection. However, state child restraint law requirements do not influence when caregivers fail to use an occupant restraint for their child passengers.     

How motorcycle helmets affect trauma mortality: Clinical and policy implications

Background: Motorcycles are the most popular vehicles in Taiwan, where more than 14.8 million motorcycles (1 motorcycle per 1.6 people) are in service. Despite the mandatory helmet law passed in 1997, less than 80% of motorcyclists in Taiwan wear helmets.

Objective: The objective of this study was to analyze the effect of using motorcycle helmets on fatality rates.

Methods: A clinical data set including 2,868 trauma patients was analyzed; the cross-sectional registration database was administered by a university medical center in Central Taiwan. A path analysis framework and multiple logistic regressions were used to estimate the marginal effect of helmet use on mortality.

Results: Using a helmet did not directly reduce the mortality rate but rather indirectly reduced the mortality rate through intervening variables such as the severity of head injuries, number of craniotomies, and complications during therapeutic processes. Wearing a helmet can reduce the fatality rate by 1.3%, the rate of severe head injury by 34.5%, the craniotomy rate by 7.8%, and the rate of complications during therapeutic processes by 1.5%. These rates comprise 33.3% of the mortality rate for people who do not wear helmets, 67.3% of the severe head injury rate, 60.0% of the craniotomy rate, and 12.2% of the rate of complications during therapeutic processes.

Discussion: Wearing a helmet and trauma system designation are crucial factors that reduce the fatality rate.     

Epidemiology and patterns of facial fractures due to road traffic accidents in Taiwan: A 15-year retrospective study

Objective: The facial region is a commonly fractured site, but the etiology varies widely by country and geographic region. To date, there are no population-based studies of facial fractures in Taiwan.

Methods: We conducted a retrospective study of patients diagnosed with facial fracture and registered in the National Health Insurance Research Database of Taiwan between 1997 and 2011. The epidemiological characteristics of this cohort were analyzed, including the etiology, fracture site, associated injuries, and sex and age distributions.

Results: A total of 6,013 cases were identified that involved facial fractures. Most patients were male (69.8%), aged 18–29 years (35.8%), and had fractures caused by road traffic accidents (RTAs; 55.2%), particularly motorcycle accidents (31.5%). Falls increased in frequency with advancing age, reaching 23.9% among the elderly (age > 65 years). The most common sites of involvement were the malar and maxillary bones (54.0%), but nasal bone fractures were more common among those younger than 18 years.

Conclusion: Most facial injuries in Taiwan occur in young males and typically result from RTAs, particularly involving motorcycles. However, with increasing age, there is an increase in the proportion of facial injuries due to falls.     

Comparison of current ATDs with Chinese adults in anthropometry

Objective: Crash test dummies are full-scale anthropomorphic test devices (ATDs) that simulate the dimensions, weight proportions, and articulation of the human body and are used to measure human injury potential in vehicle crashes. The Hybrid III dummy family, which is widely used currently, takes selected percentiles of anthropometry dimensions of U.S. adults as design references. The objective of this study was to assess the difference in anthropometry between Chinese adults and the currently used dummy.

Methods: Based on the Chinese National Physical Fitness Surveillance of the year 2000, 2005, 2010 and National Standard of China GB/T 10000–1988, a series of anthropometric parameters for Chinese adults were obtained, and data analysis was conducted between Chinese adults and ATDs that are currently used.

Results: The comparison revealed distinct anthropometric difference between ATDs and Chinese adults. Based on the latest data, median Chinese females were about 2.6% lower in stature and about 8.03% lower in body weight than the ATD design targets. Similarly, median Chinese males were about 3.48% shorter and weighed 11.89% less than the ATD design targets.

Conclusions: Although the anthropometric differences between Chinese adults and the Hybrid III ATD specifications were modest and growing smaller, it is advisable to take the differences in anthropometry between ATDs and Chinese adults into consideration when developing new vehicles in China to provide effective protection specifically for Chinese occupants.     

Observed activation status of lane departure warning and forward collision warning of Honda vehicles at dealership service centers

Objective: There are little objective data on whether drivers with lane departure warning and forward collision warning systems actually use them, but self-report data indicate that lane departure warning may be used less and viewed less favorably than forward collision warning. The current study assessed whether the systems were turned on when drivers brought their vehicles to dealership service stations and whether the observational protocol is a feasible method for collecting similar data on various manufacturers' systems.

Methods: Observations of 2013–2015 Honda Accords, 2014–2015 Odysseys, and 2015 CR-Vs occurred at 2 U.S. Honda dealerships for approximately 4 weeks during Summer 2015.

Results: Of the 265 vehicles observed to have the 2 systems, 87 (32.8%) had lane departure warning turned on. Accords were associated with a 66% increase in the likelihood that lane departure warning was turned on compared with Odysseys, but the rate was still only about 40% in Accords. In contrast, forward collision warning was turned on in all but one of the observed vehicles.

Conclusions: Observations found that the activation rate was much higher for forward collision warning than lane departure warning. The observation method worked well and appears feasible for extending to other manufacturers.     

Spatial patterns of off-the-system traffic crashes in Miami–Dade County,Florida, during 2005–2010

Objective: The objective of this study is to analyze the spatial distribution of the vehicles involved in crashes in Miami–Dade County. In addition, we analyzed the role of time of day, day of the week, seasonality, drivers’ age in the distribution of traffic crashes.

Method: Off-the-system crash data acquired from the Florida Department of Transportation during 2005–2010 were divided into subcategories according to the risk factors age, time of day, day of the week, and travel season. Various spatial statistics methods, including nearest neighbor analysis, Getis-Ord hot spot analysis, and kernel density analysis revealed substantial spatial variations, depending on the subcategory in question.

Results: Downtown Miami and South Beach showed up consistently as hotspots of traffic crashes in all subcategories except fatal crashes. However, fatal crashes were concentrated in residential areas in inland areas.

Conclusion: This understanding of patterns can help the county target high-risk areas and help to reduce crash fatalities to create a safer environment for motorists and pedestrians.     

Restraint use in the Eastern Province of the Kingdom of Saudi Arabia

Objectives: This study set out to examine seat belt and child restraint use in the Dammam Municipality of the Kingdom of Saudi Arabia, based on the premise that an increase in seat belt use would significantly reduce personal injury in traffic crashes. It was expected that local data would help identify intervention strategies necessary to improve seat belt use in the region.

Methods: The research involved 2 methodologies. First, 1,389 face-to-face interviews were conducted with male and female adults in regional shopping plazas regarding their own and their children's restraint use in their vehicles and reasons for these attitudes and beliefs. Second, 2 on-road observation studies of adult and child restraint use were conducted by trained observers. Occupants of approximately 5,000 passenger vehicles were observed while stopped at representative signalized traffic intersections.

Results: The findings showed front seat belt use rates of between 43 and 47% for drivers and 26 to 30% for front seat passengers; rear seat belt use rates were lower. While there seemed to be some knowledge about the purpose and reasons for restraining both adults and children in suitable restraints, this failed to be confirmed in the on-road observations.

Conclusions: Reasons for these rates and findings are discussed fully, and recommendations for improving seat belt use in the Dammam Municipality are included.     

The psychological impact of traffic injuries sustained in a road crash by bicyclists: A prospective study

Objective: The objective of this study was to investigate the psychological impact of traffic injuries in bicyclists (cyclists) in comparison to car occupants who also sustained traffic injuries. Factors predictive of elevated psychological distress were also investigated.

Methods: An inception cohort prospective design was used. Participants included cyclists aged ≥17 years (mean age 41.7 years) who sustained a physical injury (n = 238) assessed within 28 days of the crash, following medical examination by a registered health care practitioner. Injury included musculoskeletal and soft tissue injuries and minor/moderate traumatic brain injury (TBI), excluding severe TBI, spinal cord injury, and severe multiple fractures. Assessment also occurred 6 months postinjury. Telephone-administered interviews assessed a suite of measures including sociodemographic, preinjury health and injury factors. Psychological impact was measured by pain catastrophization, trauma-related distress, and general psychological distress. The psychological health of the cyclists was compared to that of the car occupants (n = 234; mean age 43.1 years). A mixed model repeated measures analysis, adjusted for confounding factors, was used to determine differences between groups and regression analyses were used to determine contributors to psychological health in the cyclists 6 months postinjury.

Results: Cyclists had significantly better psychological health (e.g., lower pain catastrophizing, lower rates of probable posttraumatic stress disorder [PTSD], and lower general distress levels) compared to car occupants at baseline and 6 months postinjury. Factors predictive of cyclists' psychological distress included younger age, greater perceived danger of death, poorer preinjury health, and greater amount of time in hospital after the injury.

Conclusions: These data provide insight into how cyclists perceive and adjust to their traffic injuries compared to drivers and passengers who sustain traffic injuries, as well as direction for preventing the development of severe psychological injury. Future research should examine the utility of predictors of psychological health to improve recovery.     

Injury risks for on-road farm equipment and horse and buggy crashes in Pennsylvania: 2010–2013

Objective: The purpose of this study was to investigate characteristics associated with farm equipment and horse and buggy roadway crashes in relation to person, incident, and injury characteristics to identify appropriate points for injury incident prevention.

Methods: Information on crashes occurring on public roads during the years 2010–2013 was obtained from the Pennsylvania Department of Transportation (PennDOT) and analyzed.

Results: There were 344 farm equipment and 246 horse and buggy crashes during the 4-year study period. These crashes involved 666 and 504 vehicles and 780 and 838 people, respectively. In incidents with farm equipment, the non-farm equipment drivers had an almost 2 times greater injury risk than farm equipment operators. Horse and buggy crashes were almost 3 times more injurious to the horse and buggy drivers than the drivers of the other vehicles.

Conclusions: The average crash rate for farm equipment was 198.4 crashes per 100,000 farm population and for horse and buggy the crash rate was calculated as 89.4 crashes per 100,000 Amish population per year. This study suggests that road safety and public health programs should focus not only on farm equipment operators and horse and buggy drivers but on other motorists sharing the roadway with them.     

A new method to assess the deformations of internal organs of the abdomen during impact

Objectives: Due to limitations of classic imaging approaches, the internal response of abdominal organs is difficult to observe during an impact. Within the context of impact biomechanics for the protection of the occupant of transports, this could be an issue for human model validation and injury prediction.

Methods: In the current study, a previously developed technique (ultrafast ultrasound imaging) was used as the basis to develop a protocol to observe the internal response of abdominal organs in situ at high imaging rates. The protocol was applied to 3 postmortem human surrogates to observe the liver and the colon during impacts delivered to the abdomen.

Results: The results show the sensitivity of the liver motion to the impact location. Compression of the colon was also quantified and compared to the abdominal compression.

Conclusions: These results illustrate the feasibility of the approach. Further tests and comparisons with simulations are under preparation.     

Identifying risky drivers with simulated driving

Objective: The present study aimed to examine whether high-risk drivers differ from low-risk drivers in driving behavior in a simulated environment.

Method: The 2 risk groups including 36 drivers (18 males and 18 females) performed driving tasks in a simulated environment. The simulated driving behaviors are compared between the 2 risk groups.

Results: The high-risk drivers drove much faster and exhibited larger offsets of the steering wheel than did the low-risk drivers in events without incidents. Additionally, the high-risk drivers used turn signals and horns less frequently than the low-risk drivers.

Conclusions: The present study revealed that the high-risk group differed from the low-risk group in driving behavior in a simulated environment. These results also suggest that simulated driving tasks might be useful tools for the evaluation of drivers’ potential risks.     

“Are you still driving?” Metasynthesis of patient preferences for communication with health care providers

Aim: The aim of this study was to synthesize published qualitative studies to identify older adults' preferences for communication about driving with health care providers.

Background: Health care providers play a key role in addressing driving safety and driving retirement with older adults, but conversations about driving can be difficult. Guides exist for family members and providers, but to date less is known about the types of communication and messages older drivers want from their health care providers.

Design: A qualitative metasynthesis of studies published on or before October 10, 2014, in databases (PubMed, CINAHL, PsycINFO, and Web of Science) and grey literature was performed.

Review Methods: Twenty-two published studies representing 518 older adult drivers met the following inclusion criteria: the study (1) was about driving; (2) involved older drivers; (3) was qualitative (rather than quantitative or mixed methods); and (4) contained information on older drivers' perspectives about communication with health care providers.

Results: We identified 5 major themes regarding older adults' communication preferences: (1) driving discussions are emotionally charged; (2) context matters; (3) providers are trusted and viewed as authority figures; (4) communication should occur over a period of time rather than suddenly; and (5) older adults desire agency in the decision to stop driving.

Conclusion: Various stakeholders involved in older driver safety should consider older drivers' perspectives regarding discussions about driving. Health care providers can respect and empower older drivers—and support their family members—through tactful communication about driving safety and mobility transitions during the life course.     

An empirical bayes safety evaluation of tram/streetcar signal and lane priority measures in Melbourne

Objective: Streetcars/tram systems are growing worldwide, and many are given priority to increase speed and reliability performance in mixed traffic conditions. Research related to the road safety impact of tram priority is limited. This study explores the road safety impacts of tram priority measures including lane and intersection/signal priority measures.

Method: A before–after crash study was conducted using the empirical Bayes (EB) method to provide more accurate crash impact estimates by accounting for wider crash trends and regression to the mean effects. Before–after crash data for 29 intersections with tram signal priority and 23 arterials with tram lane priority in Melbourne, Australia, were analyzed to evaluate the road safety impact of tram priority.

Results: The EB before–after analysis results indicated a statistically significant adjusted crash reduction rate of 16.4% after implementation of tram priority measures. Signal priority measures were found to reduce crashes by 13.9% and lane priority by 19.4%. A disaggregate level simple before–after analysis indicated reductions in total and serious crashes as well as vehicle-, pedestrian-, and motorcycle-involved crashes. In addition, reductions in on-path crashes, pedestrian-involved crashes, and collisions among vehicles moving in the same and opposite directions and all other specific crash types were found after tram priority implementation.

Conclusions: Results suggest that streetcar/tram priority measures result in safety benefits for all road users, including vehicles, pedestrians, and cyclists. Policy implications and areas for future research are discussed.     

Studded and unstudded winter tires in fatal road accidents in Finland

Objective: The aim of the study was to compare the safety effects of studded and unstudded winter tires based on fatal road accidents.

Methods: The data included 958 road accidents involving a passenger car or van that occurred in Finland from November to March between 1997 and 2012.

Results: Comparing the proportions of winter tire type in accidents and in general traffic showed that the overall effect of tire type on the number of accidents was not significant, although studded tires reduced fatal accidents by 10–15%. Compared to unstudded tires, studded tires reduced accidents significantly only on bald ice in 2005–2012. Drivers using unstudded tires were more experienced and their profession was more frequently related to driving. In addition, the vehicle age was lower for vehicles with unstudded tires. On the other hand, the state of repair was less pertinent for unstudded than for studded tires. These confounding factors offset their effects to some degree.

Conclusions: The risk of fatal road accidents in winter between studded and unstudded tires does not differ significantly. However, the accident risk has recently been substantially higher on bald ice for unstudded than for studded tires. The magnitude of this risk difference is difficult to determine without specific information on exposure by road surface.     

IIHS head restraint ratings and insurance injury claim rates

Objectives: The Insurance Institute for Highway Safety (IIHS) rates front seat/head restraint designs using a combination of static and dynamic measurements following RCAR-IIWPG procedures. The purpose of this study was to determine whether vehicles with better IIHS-rated seats/head restraints had lower injury risk in rear-end collisions and how the effect of better rated seats interacted with driver gender and age.

Methods: The presence of an associated insurance injury claim was determined for rear-impact crashes using 2001–2014 model year cars and SUVs. Logistic regression was used to compare injury risk for vehicles with good, acceptable, and marginal IIHS-rated seats/head restraints with poor-rated seats/head restraints. Analyses were run by gender and driver age and also by the rate of more severe injury claims.

Results: Injury rates were 11.2% lower for vehicles with seats/head restraints rated good compared to vehicles with seats/head restraints rated poor. The percentage reduction for good- versus poor-rated seats was greater for females (12.7%) than males (8.9%). Comparing good- with poor-rated seats, driver ages 15–24 had the largest reduction at 19.8%, followed by 10.7% for driver ages 45–64 and 10.4% for driver ages 25–44.

Conclusions: Seats/head restraints with better IIHS ratings are associated with lower injury rates in rear-impact collisions than seats rated poor. The reductions in injury rates were strongest for females and for young-to–middle-age drivers. The strong reductions in injury rates for these groups are encouraging given their high initial injury rates.     

Comparison of multibody and finite element human body models in pedestrian accidents with the focus on head kinematics

Objective: The objective of this study was to compare and evaluate the difference in head kinematics between the TNO and THUMS models in pedestrian accident situations.

Methods: The TNO pedestrian model (version 7.4.2) and the THUMS pedestrian model (version 1.4) were compared in one experiment setup and 14 different accident scenarios where the vehicle velocity, leg posture, pedestrian velocity, and pedestrian's initial orientation were altered. In all simulations, the pedestrian model was impacted by a sedan. The head trajectory, head rotation, and head impact velocity were compared, as was the trend when various different parameters were altered.

Results: The multibody model had a larger head wrap-around distance for all accident scenarios. The maximum differences of the head's center of gravity between the models in the global x-, y-, and z-directions at impact were 13.9, 5.8, and 5.6 cm, respectively. The maximum difference between the models in head rotation around the head's inferior–superior axis at head impact was 36°. The head impact velocity differed up to 2.4 m/s between the models. The 2 models showed similar trends for the head trajectory when the various parameters were altered.

Conclusions: There are differences in kinematics between the THUMS and TNO pedestrian models. However, these model differences are of the same magnitude as those induced by other uncertainties in the accident reconstructions, such as initial leg posture and pedestrian velocity.