Injury and fatality risks for child pedestrians and cyclists on public roads

BACKGROUND

Pedestrians and cyclists are often referred to as "vulnerable road users," yet most research is focused on fatal crashes. We used fatal and nonfatal crash data to examine risk factors (i.e., relationship to an intersection, urbanicity, crash circumstances, and vehicle type) for police-reported pedestrian and cyclist injuries on public roads among children aged 0-9 and aged 10-19. We also compared risk factors among these two age groups with adults aged 20-29 and aged 30-39.

METHODS

Crash data were obtained for 2016-2020 from the National Highway Traffic Safety Administration's Fatality Analysis Reporting System for fatal crash injuries and Crash Report Sampling System for nonfatal crash injuries. We collected data on victim demographics, roadway, and vehicle- and driver-related factors. Descriptive analyses were conducted between and within pedestrian and cyclist victims.

RESULTS

We analyzed 206,429 pedestrian injuries (36% in children aged 0-19) and 148,828 cyclist injuries (41% in children aged 0-19) from 2016 to 2020. Overall, child pedestrians had lower injury rates than adults, but children aged 10-19 had greater cycling crash rates than adults. Almost half of the pedestrian injuries in children aged 0-9 were "dart-out" injuries (43%). In the majority of the cyclist injuries, children in both age groups failed to yield to vehicles (aged 0-9 = 40% and aged 10-19 = 24%). For children and all ages included in the study, the fatality risk ratio was highest when pedestrians and cyclists were struck by larger vehicles, such as trucks and buses. Further exploration of roadway factors is presented across ages and transportation mode.

CONCLUSION

Our findings on child, driver, vehicle, and roadway factors related to fatal and nonfatal pedestrian and cyclist injuries may help to tailor prevention efforts for younger and older children.

State cannabis laws and cannabis positivity among fatally injured drivers

BACKGROUND

As of November 8, 2023, 24 states and the District of Columbia have legalized cannabis for both recreational and medical use (RMCL-states), 14 states have legalized cannabis for medical use only (MCL-states) and 12 states have no comprehensive cannabis legislation (NoCL-states). As more states legalize cannabis for recreational use, it is critical to understand the impact of such policies on driving safety.

METHODS

Using the 2019 and 2020 Fatality Analysis Reporting System data, we performed multivariable logistic regression modeling to explore the association between state level legalization status and cannabis positivity using toxicological testing data for 14,079 fatally injured drivers. We performed a sensitivity analysis by including multiply imputed toxicological testing data for the 14,876 eligible drivers with missing toxicological testing data.

RESULTS

Overall, 4702 (33.4%) of the 14,079 fatally injured drivers tested positive for cannabis use. The prevalence of cannabis positivity was 30.7% in NoCL-states, 32.8% in MCL-states, and 38.2% in RMCL-states (p < 0.001). Compared to drivers fatally injured in NoCL-states, the adjusted odds ratios of testing positive for cannabis were 1.09 (95% confidence interval: 0.99, 1.19) for those fatally injured in MCL-states and 1.54 (95% confidence interval: 1.34, 1.77) for those fatally injured in RMCL-states. Sensitivity analysis yielded similar results.

CONCLUSIONS

Over one-third of fatally injured drivers tested positive for cannabis use. Drivers fatally injured in states with laws permitting recreational use of cannabis were significantly more likely to test positive for cannabis use than those in states without such laws. State medical cannabis laws had little impact on the odds of cannabis positivity among fatally injured drivers.

A systematic review and meta-analysis of data linkage between motor vehicle crash and hospital-based datasets

Motor vehicle crash data linkage has emerged as a vital tool to better understand the injury outcomes and the factors contributing to crashes. This systematic review and meta-analysis aims to explore the existing knowledge on data linkage between motor vehicle crashes and hospital-based datasets, summarize and highlight the findings of previous studies, and identify gaps in research. A comprehensive and systematic search of the literature yielded 54 studies for a qualitative analysis, and 35 of which were also considered for a quantitative meta-analysis. Findings highlight a range of viable methodologies for linking datasets, including manual, deterministic, probabilistic, and integrative methods. Designing a linkage method that integrates different algorithms and techniques is more likely to result in higher match rate and fewer errors. Examining the results of the meta-analysis reveals that a wide range of linkage rates were reported. There are several factors beyond the approach that affect the linkage rate including the size and coverage of both datasets and the linkage variables. Gender, age, crash type, and roadway geometry at the crash site were likely to be associated with a record's presence in a linked dataset. Linkage rate alone is not the only important metric and when linkage rate is used as a metric in research, both police and hospital rates should be reported. This study also highlights the importance of examining and accounting for population and bias introduced by linking two datasets.

Impact of alcohol driving-while-impaired license suspension duration on future alcohol-related license events and motor vehicle crash involvement in North Carolina, 2007 to 2016

BACKGROUND/PURPOSE

License suspensions are a strategy to address alcohol-impaired driving behavior and recidivism following an alcohol driving while impaired (alcohol-DWI) conviction. Little is known about the specific impacts of conviction-related suspensions on safety outcomes and given recent fluctuations in alcohol-impaired driving behavior, crashes, and suspension trends, updated and focused assessments of this intervention are necessary. This study aimed to 1) examine the association between type of recent alcohol-DWI suspension and having a secondary alcohol-related license outcome and/or future crash event in North Carolina (NC) between 2007 and 2016; and 2) assess potential modification of these associations by race/ethnicity.

METHODS

We used linked NC licensing data, NC crash data, and county-level contextual data from a variety of data sources. We compared individuals ages 21 to 64 who sustained initial (1-year) versus repeat (4-year) suspensions for alcohol-related license and crash involvement outcomes. We estimated unadjusted and adjusted hazard ratios (aHRs) using Cox proportional hazards models and produced Kaplan-Meier (KM) survival curves using a three-year follow-up period. After observing statistically significant modification by race/ethnicity, we calculated stratified aHRs for each outcome (Black and White subgroups only, as other subgroups had low numbers of outcomes).

RESULTS

122,002 individuals sustained at least one alcohol-DWI conviction suspension (117,244 initial, 4,758 repeat). Adjusted KM survival curves indicated that within three years of the index suspension, the predicted risks of having a license outcome and crash outcome were about 8 % and 15 %, respectively, among individuals with an initial suspension and 5 % and 10 %, respectively, among individuals with a repeat suspension. After adjusting for potential confounding, we found that compared to those with an initial suspension, those with repeat suspensions had a lower incidence of future license (aHR: 0.49; 95 % CI: 0.42, 0.57) and crash outcomes (aHR: 0.67; 95 % CI: 0.60, 0.75). Among Black individuals, license outcome incidence was 162 % lower among repeat versus initial index suspension groups (aHR: 0.38; 95 % CI: 0.26, 0.55), while for White individuals, the incidence was 87 % lower (aHR: 0.54; 95 % CI: 0.45, 0.64). Similarly, crash incidence for repeat versus initial suspensions among Black individuals was 56 % lower (aHR: 0.64; 95 % CI: 0.50, 0.83), while only 39 % lower among White individuals (aHR: 0.72; 95 % CI: 0.63, 0.81).

CONCLUSIONS

Decreased incidence of both license and crash outcomes were observed among repeat versus initial index suspensions. The magnitude of these differences varied by race/ethnicity, with larger decreases in incidence among Black compared to White individuals. Future research should examine the underlying mechanisms leading to alcohol-impaired driving behavior, convictions, recidivism, and crashes from a holistic social-ecological perspective so that interventions are designed to both improve road safety and maximize other critical public health outcomes, such as access to essential needs and services (e.g., healthcare and employment).

A systematic review of the impact of brain tumours on risk of motor vehicle crashes

PURPOSE

Brain tumours are associated with neurocognitive impairments that are important for safe driving. Driving is vital to maintaining patient autonomy, despite this there is limited research on driving capacity amongst patients with brain tumours. The purpose of this review is to examine MVC risk in patients with brain tumours to inform development of clearer driving guidelines.

METHODS

A systematic review was performed using Medline and EMBASE. Observational studies were included. The outcome of interest was MVC or measured risk of MVC in patients with benign or malignant brain tumours. Descriptive analysis and synthesis without meta-analysis were used to summarise findings. A narrative review of driving guidelines from Australia, United Kingdom and Canada was completed.

RESULTS

Three studies were included in this review. One cohort study, one cross-sectional study and one case-control study were included (19,135 participants) across United States and Finland. One study evaluated the incidence of MVC in brain tumour patients, revealing no difference in MVC rates. Two studies measured MVC risk using driving simulation and cognitive testing. Patients found at higher risk of MVC had greater degrees of memory and visual attention impairments. However, predictive patient and tumour characteristics of MVC risk were heterogeneous across studies. Overall, driving guidelines had clear recommendations on selected conditions like seizures but were vague surrounding neurocognitive deficits.

CONCLUSION

Limited data exists regarding driving behaviour and MVC incidence in brain tumour patients. Existing guidelines inadequately address neurocognitive complexities in this group. Future studies evaluating real-world data is required to inform development of more applicable driving guidelines.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO 2023 CRD42023434608.

Risks of motor vehicle crash before and during pregnancy: A population-based controlled study in Taiwan

BACKGROUND

Changes in risk of motor vehicle crashes (MVCs) during pregnancy are less known, and very few studies have assessed this issue by using unselected population-based datasets and adopting a before-and-during design. The study aimed to address the risk of MVC events in association with pregnancy using a national pregnant women cohort in Taiwan.

METHODS

We conducted a self-matched design in which each woman served as a driver before and during pregnancy. A total of 1,372,664 pregnant women with live birth(s) at 18-50 years of age between 2008 and 2017 were identified from the Birth Notification dataset. MVC events as a driver were ascertained from the Police-reported Traffic Accident Registry dataset. We calculated the rate ratio (RR) with a 95 % confidence interval (CI) using the conditional Poisson regression model to compare the MVC event rates between pre-pregnancy and pregnancy periods.

RESULTS

The overall rate of MVC events was significantly reduced during pregnancy (RR = 0.69, 95 % confidence interval (CI) = 0.68-0.71). Mothers with alcoholism during pregnancy were associated with an increased RR at 2.00 but with a very wide CI. Reduction in RR was primarily attributed to the reduced MVC event rate involving scooter crashes (0.60, 95 % CI = 0.58-0.62).

CONCLUSION

Although MVC event rates decreased during women became pregnant, many women drivers were still involved in MVCs during pregnancy. Their potential maternal and perinatal conditions along with their offspring's health outcomes need further investigations.

Promoting transportation safety in adolescence: the drivingly randomized controlled trial

BACKGROUND

The impact of young drivers' motor vehicle crashes (MVC) is substantial, with young drivers constituting only 14% of the US population, but contributing to 30% of all fatal and nonfatal injuries due to MVCs and 35% ($25 billion) of the all medical and lost productivity costs. The current best-practice policy approach, Graduated Driver Licensing (GDL) programs, are effective primarily by delaying licensure and restricting crash opportunity. There is a critical need for interventions that target families to complement GDL. Consequently, we will determine if a comprehensive parent-teen intervention, the Drivingly Program, reduces teens' risk for a police-reported MVC in the first 12 months of licensure. Drivingly is based on strong preliminary data and targets multiple risk and protective factors by delivering intervention content to teens, and their parents, at the learner and early independent licensing phases.

METHODS

Eligible participants are aged 16-17.33 years of age, have a learner's permit in Pennsylvania, have practiced no more than 10 h, and have at least one parent/caregiver supervising. Participants are recruited from the general community and through the Children's Hospital of Philadelphia's Recruitment Enhancement Core. Teen-parent dyads are randomized 1:1 to Drivingly or usual practice control group. Drivingly participants receive access to an online curriculum which has 16 lessons for parents and 13 for teens and an online logbook; website usage is tracked. Parents receive two, brief, psychoeducational sessions with a trained health coach and teens receive an on-road driving intervention and feedback session after 4.5 months in the study and access to DriverZed, the AAA Foundation's online hazard training program. Teens complete surveys at baseline, 3 months post-baseline, at licensure, 3months post-licensure, 6 months post-licensure, and 12 months post-licensure. Parents complete surveys at baseline, 3 months post-baseline, and at teen licensure. The primary end-point is police-reported MVCs within the first 12 months of licensure; crash data are provided by the Pennsylvania Department of Transportation.

DISCUSSION

Most evaluations of teen driver safety programs have significant methodological limitations including lack of random assignment, insufficient statistical power, and reliance on self-reported MVCs instead of police reports. Results will identify pragmatic and sustainable solutions for MVC prevention in adolescence.

TRIAL REGISTRATION

ClinicalTrials.gov # NCT03639753.

Traffic violator school masked convictions: California finally got it right

INTRODUCTION

The negative traffic safety impact of California's prior traffic violator school (TVS) citation dismissal policy is well documented in past California TVS evaluations.

METHOD

Using advanced inferential statistical techniques, the current study evaluated the substantive changes to California's traffic violator school program as required by California Assembly Bill (AB) 2499. The program changes implemented by AB 2499 appear to be associated with a specific deterrent effect as evidenced by a reliable and statistically significant reduction in subsequent traffic crashes of those receiving a masked TVS conviction as opposed to a countable conviction.

RESULTS

The results suggest that this relationship exists primarily among TVS drivers with less elevated prior records. The change in status from a TVS citation dismissal to a TVS masked conviction has reduced the negative traffic safety impact of the TVS citation dismissal policy in effect prior to the implementation of AB 2499. Several recommendations are offered to enhance the positive traffic safety impact of the TVS program by further combining its educational elements with the state's post license control program by way of the Negligent Operator Treatment System.

PRACTICAL APPLICATIONS

The findings and recommendations have implications to all states and jurisdictions utilizing pre-conviction diversion programs and/or demerit point systems associated with traffic violations.

Spinal injury rates and specific causation in motor vehicle collisions

Motor vehicle collisions (MVCs) are a leading cause of acute spinal injuries. Chronic spinal pathologies are common in the population. Thus, determining the incidence of different types of spinal injuries due to MVCs and understanding biomechanical mechanism of these injuries is important for distinguishing acute injuries from chronic degenerative disease. This paper describes methods for determining causation of spinal pathologies from MVCs based on rates of injury and analysis of the biomechanics require to produce these injuries. Rates of spinal injuries in MVCs were determined using two distinct methodologies and interpreted using a focused review of salient biomechanical literature. One methodology used incidence data from the Nationwide Emergency Department Sample and exposure data from the Crash Report Sample System supplemented with a telephone survey to estimate total national exposure to MVC. The other used incidence and exposure data from the Crash Investigation Sampling System. Linking the clinical and biomechanical findings yielded several conclusions. First, spinal injuries caused by an MVC are relatively rare (511 injured occupants per 10,000 exposed to an MVC), which is consistent with the biomechanical forces required to generate injury. Second, spinal injury rates increase as impact severity increases, and fractures are more common in higher-severity exposures. Third, the rate of sprain/strain in the cervical spine is greater than in the lumbar spine. Fourth, spinal disc injuries are extremely rare in MVCs (0.01 occupants per 10,000 exposed) and typically occur with concomitant trauma, which is consistent with the biomechanical findings 1) that disc herniations are fatigue injuries caused by cyclic loading, 2) the disc is almost never the first structure to be injured in impact loading unless it is highly flexed and compressed, and 3) that most crashes involve predominantly tensile loading in the spine, which does not cause isolated disc herniations. These biomechanical findings illustrate that determining causation when an MVC occupant presents with disc pathology must be based on the specifics of that presentation and the crash circumstances and, more broadly, that any causation determination must be informed by competent biomechanical analysis.

Increase in trauma volume as compared to emergency department volume during the COVID-19 pandemic

BACKGROUND

During the months between April through June 2020 when we experienced the largest number of COVID-19 patients in our hospital, the volume of patients in the Emergency Department (ED) was decreased by more than 30%. In contrast to most early reports we did not notice a decrease in trauma volume during this time period.

MATERIALS AND METHODS

We compared trauma patients presenting to our Level III Trauma Center, between April 2019 through June 2019 to those presenting from April 2020 through June 2020, the initial surge in COVID-19 patients. We compared ground level falls (GLF), motor vehicle crashes (MVC), bicycle and skateboard crashes, assault, and other.

RESULTS

There was a 13% increase in trauma patients presenting during the study period in 2020 as compared to 2019, and the total number of trauma patients as a percentage of total ED patients also increased 269/9235 (2.9%) to 308/6216 (5.0%), P < 0.0001. There was no significant difference in demographics or outcome data between the trauma patients presenting during the two time periods. Although traffic decreased by more than 40%, the number of MVC's was similar.

CONCLUSION

The volume of patients presenting to our Trauma Center as compared to the total ED volume increased during the time period from April through June 2020 versus the year just prior to the COVID-19 pandemic. Despite the fact that the total traffic volume decreased more than 40 percent between these two time periods, the actual number of motor vehicle crashes remained similar.

Seat belt laws and prevalence of use among high school students in the United States

PURPOSE

To examine the association between state seat belt laws and the prevalence of seat belt use among a nationally representative sample of teenagers in the United States, taking into consideration state-specific child restraint laws that could affect teenagers of different ages.

METHODS

Data were from the 2019 state Youth Risk Behavior Survey. We estimated prevalence ratios using modified Poisson regression with robust variance estimates to evaluate associations between state seat belt laws and seat belt use.

RESULTS

Among, 81,929 high school students under 18 from 36 states, 56% always wore a seat belt when someone else was driving. Relative to students in states with secondary enforcement of seat belt laws, students living in states with primary enforcement were 5% more likely (aPR = 1.05, 95% CI: 0.99, 1.11), and students covered by a child restraint law were 6% more likely to always wear a seat belt (aPR = 1.06, 95% CI: 0.99, 1.12) after adjusting for age, sex, race/ethnicity, and graduated driver licensing laws.

CONCLUSIONS

States with secondary seat belt enforcement should consider upgrading seat belt laws to potentially improve the prevalence of seat belt use among adolescents, potentially reducing injuries and deaths due to motor vehicle crashes.

Piloting a hospital-based road traffic injury surveillance system in Nairobi County, Kenya, 2018-2019

BACKGROUND

Kenya's estimated road traffic injury (RTI) death rate is 27.8/100,000 population, which is 1.5 times the global rate. Some RTI data are collected in Kenya; however, a systematic and integrated surveillance system does not exist. Therefore, we adopted and modified the World Health Organization's injury surveillance guidelines to pilot a hospital-based RTI surveillance system in Nairobi County, Kenya.

METHODS

We prospectively documented all RTI cases presenting at two public trauma hospitals in Nairobi County from October 2018-April 2019. RTI cases were defined as injuries involving ≥1 moving vehicles on public roads. Demographics, injury circumstances, and outcome information were collected using standardized case report forms. The Kampala Trauma Score (KTS) was used to assess injury severity. RTI cases were characterized with descriptive statistics.

RESULTS

Of the 1,840 RTI cases reported during the seven-month period, 73.2% were male. The median age was 29.8 years (range 1-89 years). Forty percent (n = 740) were taken to the hospital by bystanders. Median time for hospital arrival was 77 min. Pedestrians constituted 54.1% (n = 995) of cases. Of 400 motorcyclists, 48.0% lacked helmets. Similarly, 65.7% of bicyclists (23/35) lacked helmets. Among 386 motor vehicle occupants, 59.6% were not using seat belts (19.9% unknown). Seven percent of cases (n = 129) reported alcohol use (49.0% unknown), and 8.8% (n = 161) reported mobile phone use (59.7% unknown). Eleven percent of cases (n = 199) were severely injured (KTS <11), and 220 died.

CONCLUSION

We demonstrated feasibility of a hospital-based RTI surveillance system in Nairobi County. Integrating information from crash scenes and hospitals can guide prevention.

Human Lumbar Spine Injury Risk in Dynamic Combined Compression and Flexion Loading

Anticipating changes to vehicle interiors with future automated driving systems, the automobile industry recently has focused attention on crash response in novel postures with increased seatback recline. Prior research found that this posture may result in greater risk of lumbar spine injury in the event of a frontal crash. This study developed a lumbar spine injury risk function (IRF) that estimated injury risk as a function of simultaneously applied compression force and flexion moment. Force and moment failure data from 40 compression-flexion tests were utilized in a Weibull survival model, including appropriate data censoring. A mechanics-based injury metric was formulated, where lumbar spine compression force and flexion moment were normalized by specimen geometry. Subject age was incorporated as a covariate to further improve model fit. A weighting factor was included to adjust the influence of force and moment, and parameter optimization yielded a value of 0.11. Thus, the normalized compression force component had a greater effect on injury risk than the normalized flexion moment component. Additionally, as force was nominally increased, less moment was required to produce injury for a given age and specimen geometry. The resulting IRF may be utilized to improve occupant safety in the future.

Ambient temperature and risk of motor vehicle crashes: A countrywide analysis in Spain

BACKGROUND

Some studies have documented that cold or hot ambient temperatures increase the risk of motor vehicle crashes. However, the number of existing studies is still limited, especially for the effects of cold.

OBJECTIVES

To estimate the relationship between ambient temperatures and risk of motor vehicle crashes in Spain, and to estimate the same association when restricting to those crashes with driver performance-associated factors (namely distraction, fatigue, sleepiness or disease).

METHODS

We used data for the period 1993-2013. We conducted a time series analysis controlling for seasonality and trends and using the distributed lag nonlinear model framework to estimate nonlinear and delayed effects of up to 7 days. Analyses were conducted at the province level and combined using multivariate meta-analysis.

RESULTS

The study included 1,908,460 motor vehicle crashes, 37% of them with associated driver performance factors. The overall analysis showed that the risk of crashes increased almost linearly with temperature. The estimates of the cumulative effect of lags 0-7 when comparing the 99th percentile and the first percentile of temperature produced a relative risk (RR) of 1.15 (95% confidence interval (CI): 1.11, 1.20). The estimates were slightly higher when analyses were restricted to crashes with driver performance-associated factors (RR: 1.23, 95% CI: 1.17, 1.30). In some provinces that reached temperatures below 0 °C, an increased risk with cold temperatures was also observed. An added effect of both cold spell and heat wave periods was found only in the analysis of crashes with driver performance-associated factors (cold spells, RR: 1.029, 95% CI: 1.005, 1.053; heat waves, RR: 1.020, 95% CI: 1.002, 1.039).

CONCLUSIONS

The increase of temperature increased the risk of motor vehicle crashes in Spain. Measures aimed at reducing the influence of heat on the risk of motor vehicle crashes can have important benefits for public health.

National trends in pediatric firearm and automobile fatalities

BACKGROUND

Successful public health policies and injury prevention efforts have reduced pediatric automobile fatalities across the United States. In 2019, firearm injuries exceeded motor vehicle crashes (MVC) as the leading cause of childhood death in Colorado. We sought to determine if similar trends exist nationally and if state gun laws impact firearm injury fatality rates.

METHODS

Annual pediatric (≤19 years-old) fatality rates for firearm injuries and MVCs were obtained from the CDC WONDER database (1999-2020). State gun law scores were based on the 2014-2020 Gifford's Annual Gun Law Scorecard and strength was categorized by letter grades A-F. Poisson generalized linear mixed models were used to model fatality rates. Rates were estimated for multiple timepoints and compared between grade levels.

RESULTS

In 1999, the national pediatric fatality rate for MVCs was 248% higher than firearm injuries (Incidence Rate Ratio (IRR) 95% Confidence Interval (CI): 2.25-2.73, p<0.0001). By 2020, the fatality rate for MVCs was 16% lower than that of firearm injuries (IRR 95% CI: 0.75- 0.93, p = 0.0014). For each increase in letter grade for gun law strength there was an 18% reduction in the firearm fatality rate (IRR 95%CI: 0.78-0.86, p<0.0001). States with the strongest gun laws (A) had a 55% lower firearm fatality rate compared to those with the weakest laws (F).

CONCLUSION

Firearm injuries are the leading cause of death in pediatric patients across the United States. State gun law strength has a significant impact on pediatric firearm injury fatality rates. New public health policies, political action, media attention and safer guns are urgently needed to curb this national crisis.

LEVEL OF EVIDENCE/STUDY TYPE

Level III, retrospective.

Assessing the Australian occupational driver behavior questionnaire in U.S. taxi drivers: Different country, different occupation and different worker population

BACKGROUND

Promoting safe driver behaviors is an important aspect of road safety. To better understand road safety behaviors, there is a role for practical instruments that can validly measure typical road safety behaviors among occupational drivers. The Occupational Driver Behavior Questionnaire (ODBQ) was developed to assess road safety behaviors among home health nurses in Australia.

METHODS

We administered a cross-sectional survey to a sample of taxi drivers in two U.S. metropolitan areas. The survey included Newnam's ODBQ-12 and a study-specific 15-item version (ODBQ-15) assessing 4 different road safety behaviors with 3 more items added and motor-vehicle crashes in the past year. Logistic regression analyses examined the association of the road safety behaviors with motor vehicle crashes. A series of confirmatory factor analysis (CFA) models assessed the construct validity of the ODBQ-12 and ODBQ-15.

RESULTS

We pooled survey data from 497 Houston drivers and 500 Los Angeles drivers to assess study aims. CFA models examining the 12-item and the 15-item ODBQ versions had good model fit (Comparative Fit Index > 0.95, Tucker Lewis Index ≥ 0.95, root mean square error of approximation < 0.06, standardized root mean square residual ≤ 0.05). The ODBQ's road safety behaviors were significantly associated (p < 0.001) with crashes while working (ORs 0.51-0.75) and not working (ORs 0.57-0.84).

CONCLUSIONS

The ODBQ-12 and ODBQ-15 were both significantly associated with motor vehicle crashes among taxicab drivers in two large U.S. metropolitan areas. Researchers studying occupational drivers who transport passengers may want to consider using the ODBQ-15. The 3 additional items are meaningful to this workforce and are priority areas for international road safety efforts.

Ambient temperatures associated with increased risk of motor vehicle crashes in New York and Chicago

Motor Vehicle Crashes (MVC) are a major cause of death and disability worldwide. Yet it remains unknown to what extent changes in cold and hot temperatures affect the MVC. Here we quantify the linkage between ambient temperature exposure and the MVC risk of the driver in four cities of the United States. After adjusting for confounding factors, we find both a cold effect and a hot effect on MVC in New York, and a cold effect on MVC in Chicago. A 1 °C decrease in mean daily temperature below a cold threshold of -4.8 °C is associated with an increase in the overall cumulative relative risk of MVC by 11.59% (95% CI: 5.17%-16.43%) over 0-28 lag days for New York. The respective risk increase is 1.58% (95% CI: 0.36%-2.79%) over 0-2 lag days for a 1 °C increase in mean daily temperature above the hot threshold of 26.1 °C for New York. There is no significant heat wave or cold spell effects except for the heat wave effect on the consecutive heat wave days 7-10 in New York. Our study provides evidence of the association between driver exposure to low or high temperatures and the MVC risk. Improved public- administration preventive measures and policymaking are needed to minimize the negative consequences of abnormal temperatures on road safety driving.

Improving identification of crash injuries: Statewide integration of hospital discharge and crash report data

OBJECTIVE

The availability of complete and accurate crash injury data is critical to prevention and intervention efforts. Relying solely on hospital discharge data or police crash reports may result in a biased undercount of injuries. Linking hospital data with crash reports may allow for a more robust identification of injuries and an understanding of which populations may be missed in an analysis of one source. We used the New Jersey Safety and Health Outcomes (NJ-SHO) data warehouse to examine the share of the entire crash-injured population identified in each of the two data sources, overall and by age, race/ethnicity, sex, injury severity, and road user type.

METHODS

We utilized 2016-2017 data from the NJ-SHO warehouse. We identified crash-involved individuals in hospital discharge data by applying the ICD-10-CM external cause of injury matrix. Among crash-involved individuals, we identified those with injury- or pain-related diagnosis codes as being injured. We also identified crash-involved individuals via crash report data and identified injuries using the KABCO scale. We jointly examined the two sources; injuries in the hospital discharge data were documented as being related to the same crash as injuries found in the crash report data if the date of the crash report preceded the date of hospital admission by no more than two days.

RESULTS

In total, there were 262,338 crash-involved individuals with a documented injury in the hospital discharge data or on the crash report during the study period; 168,874 had an injury according to hospital discharge data, and 164,158 had an injury in crash report data. Only 70,694 (26.9%) had an injury in both sources. We observed differences by age, race/ethnicity, injury severity, and road user type: hospital discharge data captured a larger share of those ages 65+, those who were Black or Hispanic, those with higher severity injuries, and those who were bicyclists or motorcyclists.

CONCLUSIONS

Each data source in isolation captures approximately two-thirds of the entire crash-injured population; one source alone misses approximately one-third of injured individuals. Each source undercounts people in certain groups, so relying on one source alone may not allow for tailored prevention and intervention efforts.

Motor vehicle crashes on tribal reservations: mapping and statistics

Background

Motor vehicle crashes (MVC’s) in the American Indian/Alaska Native (AI/AN) communities account for 43% of unintentional injury deaths. This article introduces MVC data and geographic information system (GIS) mapping for tribal reservations.

Methods

Utilizing a sample of Montana Department of Transportation (DOT) data for the Flathead reservations to calculate frequencies and proportions of crash types (i.e., property damage or no-injury, injury, fatality or unknown), while also mapping these data to provide a cross-sectional snapshot of MVC’s.

Results

Overall, 515 MVC’s occurred for years 2016 through 2018, with no-injury, injury, and fatality accounting for 72.2%, 24.9% and 1.8% of all crashes, respectively, with the number of MVC’s ranging up to 30 per square mile.

Conclusion

Examining DOT data and utilizing it for visual representation of MVC’s can be used as an additional source in uncovering patterns and trends on Tribal reservations and supporting MVC prevention efforts.

Evaluation of motor vehicle crash rates during and after the COVID-19-associated stay-at-home order in Connecticut

INTRODUCTION

Recent research suggests that COVID-19 associated stay-at-home orders, or shelter-in-place orders, have impacted intra-and-interstate travel as well as motor vehicle crashes (crashes). We sought to further this research and to understand the impact of the stay-at-home order on crashes in the post order period in Connecticut.

METHODS

We used a multiple-comparison group, interrupted time-series analysis design to compare crashes per 100 million vehicle miles traveled (VMT) per week in 2020 to the average of 2017-2019 from January 1-August 31. We stratified crash rate by severity and the number of vehicles involved. We modeled two interruption points reflecting the weeks Connecticut implemented (March 23rd, week 12) and rescinded (May 20th, week 20) its stay-at-home order.

RESULTS

During the initial week of the stay-at-home order in Connecticut, there was an additional 28 single vehicle crashes compared to previous years (95% confidence interval (CI): [15.8, 36.8]). However, the increase at the order onset was not seen throughout the duration. Rescinding the stay-at-home order by and large did not result in an immediate increase in crash rates. Crash rates steadily returned to previous year averages during the post-stay-at-home period. Fatal crash rates were unaffected by the stay-at-home order and remained similar to previous year rates throughout the study duration.

DISCUSSION

The initial onset of the stay-at-home order in Connecticut was associated with a sharp increase in the single vehicle crash rate but that increase was not sustained for the remainder of the stay-at-home order. Likely changes in driver characteristics during and after the order kept fatal crash rates similar to previous years.

What factors impact pedestrian and cyclist fatalities? A state level analysis

Background

Pedestrian and bicyclist injuries and fatalities have increased since 2010 after a long downward trend. Trucks and SUVs, collectively called light trucks, have also increased in sales and size, which may affect pedestrians and bicyclists. Additionally, pedestrian and cyclist commuters vary by state and it has been speculated that an increase in such commuters may affect fatalities. Studying vulnerable road users can bestow clues on best practices for infrastructure and public health.

Methods

State level pedestrian and cyclist fatality data was obtained from the National Highway Transportation Safety Administration for 2018. Light truck registration by state was obtained from the Office of Highway Policy Information for 2018. Commuters who walk or bike to work were obtained from the American Community Survey from 2009 to 2011, from the latest Centers for Disease Control report. We performed multiple linear regression, accounting for total motor vehicle lane miles per 100 people, also obtained from the Office of Highway Policy Information for 2018. Multiple regression analysis was performed to assess predictors for pedestrian and cyclist fatalities with the predictors variables of light truck registration, lane miles per 100 people, and proportion of commuters who are vulnerable road users. Secondary analysis included simple linear regression of the predictor variables against each other.

Results

The multiple regression model, including proportion of light truck registration, lane miles per 100 people, and proportion of commuters who are vulnerable road users, accounted for 18% of the variability in the outcome variable (p = 0.03). An increased number of vulnerable road users were negatively associated with pedestrian and bicyclist fatality. Additionally, there appeared to be an association between motor vehicle lane miles per 100 people and proportion of light truck registrations that was also significant (p < 0.01).

Conclusion

The variables affecting vulnerable road user deaths are important to understand given their increased risk exposure on the road. This state level study identifies a potential protective variable with increased vulnerable road users being associated with a decrease in pedestrian and bicyclist death rates. Additionally, light truck proportions do not appear to have a significant effect on death rates.

A data-driven, kinematic feature-based, near real-time algorithm for injury severity prediction of vehicle occupants

Accurate real-time prediction of occupant injury severity in unavoidable collision scenarios is a prerequisite for enhancing road traffic safety with the development of highly automated vehicles. Specifically, a safety prediction model provides a decision reference for the trajectory planning system in the pre-crash phase and the adaptive restraint system in the in-crash phase. The main goal of the current study is to construct a data-driven, vehicle kinematic feature-based model to realize accurate and near real-time prediction of in-vehicle occupant injury severity. A large-scale numerical database was established focusing on occupant kinetics. A first-step deep-learning model was established to predict occupant kinetics and injury severity using a convolutional neural network (CNN). To reduce the computational time for real-time application, the second step was to extract simplified kinematic features from vehicle crash pulses via a feature extraction method, which was inspired by a visualization approach applied to the CNN-based model. The features were incorporated with a low-complexity machine-learning algorithm and achieved satisfactory accuracy (85.4 % on the numerical database, 78.7 % on a 192-case real-world dataset) and decreased computational time (1.2 ± 0.4 ms) on the prediction tasks. This study demonstrated the feasibility of using data-driven and feature-based approaches to achieve accurate injury risk estimation prior to collision. The proposed model is expected to provide a decision reference for integrated safety systems in the next generation of automated vehicles.

So much nuance: A qualitative analysis of parental perspectives on child passenger safety

OBJECTIVE

To explore barriers and facilitators to optimal child restraint system (CRS) use for diverse parents of newborn infants and to obtain input from parents on the use of technology-assisted remote car seat checks as tools for promoting optimal CRS use.

METHODS

Parents were recruited using purposive sampling. Interviews were conducted with English- or Spanish-speaking parents with a full term newborn and regular access to a car. Interviews were conducted by phone, and recorded and transcribed verbatim. Interviews were conducted until thematic saturation was reached. Data were organized for analysis using Atlas.ti, and codes grouped by theme using constant comparison.

RESULTS

30 parents were enrolled. Barriers and facilitators to optimal CRS use were classified into three themes, as were thoughts on the pros and cons regarding remote car seat checks. Themes on barriers and facilitators included motor vehicle and CRS features (such as age and size of the motor vehicle and presence of the Lower Anchors and Tethers for Children LATCH system), resources (availability, accessibility, and accuracy of resources), and parental factors (parental emotions and characteristics). Themes related to pros and cons of remote car seat checks included the ability (and challenge) of remote car seat checks to identify and correct errors, the potential use of remote car seat checks in certain situations (such as CRS transitions and periods of growth), and convenience of remote car seat checks (including increased availability and ease of access). Subthemes with further detail were arranged within each theme identified.

CONCLUSION

From a parent perspective, there are several identified barriers and facilitators of optimal CRS use. Although car seat checks were identified as a resource, in-person accessibility was an issue, and there were mixed opinions on technology-assisted remote car seat checks. These results provide a foundation for additional study on targeted interventions, including remote interventions for which there is an increased need due to the COVID-19 pandemic.

Advancing our understanding of cognitive development and motor vehicle crash risk: A multiverse representation analysis

Neurobiological and cognitive maturational models are the dominant theoretical account of adolescents' risk-taking behavior. Both the protracted development of working memory (WM) through adolescence, as well as individual differences in WM capacity have been theorized to be related to risk-taking behavior, including reckless driving. In a cohort study of 84 adolescent drivers Walshe et al. (2019) found adolescents who crashed had an attenuated trajectory of WM growth compared to adolescent drivers who never reported being in a crash, but observed no difference in WM capacity at baseline. The objectives of this report were to attempt to replicate these associations and to evaluate their robustness using a hybrid multiverse - specification curve analysis approach, henceforth called multiverse representation analysis (MRA). The authors of the original report provided their data: 84 adolescent drivers with annual evaluations of WM and other risk factors from 2005 to 2013, and of driving experiences in 2015. The original analysis was implemented as described in the original report. An MRA approach was used to evaluate the robustness of the association between developmental trajectories of WM and adolescents' risk-taking (indexed by motor vehicle crash involvement) to different reasonable methodological choices. We enumerated 6 reasonable choice points in data processing-analysis configurations: (1) model type: latent growth or multi-level regression, (2) treatment of WM data; (3) which waves are included; (4) covariate treatment; (5) how time is coded; and (6) link function/estimation method: weighted least squares means and variance estimation (WLSMV) with a linear link versus logistic regression with maximum likelihood estimation. This multiverse consists of 96 latent growth models and 18 multi-level regression models.

Direct and indirect effects of marijuana use on the risk of fatal 2-vehicle crash initiation

BACKGROUND

Marijuana and alcohol each play a significant role in fatal crash initiation. We decomposed the total effect of marijuana use in the presence or absence of alcohol on fatal crash initiation into direct and indirect effects.

METHODS

Pair-matched data on 5856 culpable drivers (initiators) and 5856 nonculpable drivers (noninitiators) involved in the same fatal 2-vehicle crashes recorded in the Fatality Analysis Reporting System between 2011 and 2016 were analyzed using the conditional logistic regression model and the unified mediation and interaction analysis framework.

RESULTS

Crash initiators were more likely than noninitiators to test positive for marijuana (16.1% vs. 9.2%, P < 0.001), alcohol (28.6% vs. 9.7%, P < 0.001) and both substances (6.3% vs. 1.6%, P < .0001). Adjusted odds ratios of fatal 2-vehicle crash initiation revealed a positive interaction on the additive scale between marijuana and alcohol. Of the total effect of marijuana use on fatal 2-vehicle crash initiation, 68.8% was attributable to the direct effect (51.5% to controlled direct effect and 17.3% to reference interaction effect with alcohol) and 31.2% to the indirect effect (7.8% to mediated interaction effect and 23.4% to pure indirect effect through alcohol).

CONCLUSION

Our results indicate that the increased odds of fatal 2-vehicle crash initiation associated with marijuana use is due mainly to the direct effect.

The effect of extending graduated driver licensing to older novice drivers in Indiana

INTRODUCTION

Graduated driver licensing (GDL) systems have been shown to reduce rates of crashes, injuries, and deaths of young novice drivers. However, approximately one in three new drivers in the United States obtain their first driver's license at age 18 or older, and thus are exempt from most or all provisions of GDL in most states.

METHOD

In July 2015, the state of Indiana updated its GDL program, extending its restrictions on driving at night and on carrying passengers during the first 6 months of independent driving, previously only applicable to new drivers younger than 18, to all newly-licensed drivers younger than 21 years of age. The current study examined monthly rates of crashes per licensed driver under the affected conditions (driving at night and driving with passengers) among Indiana drivers first licensed at ages 18, 19, and 20 under the updated GDL system compared with drivers licensed at the same ages under the previous GDL system. We used Poisson regression to estimate the association between the GDL system and crash rates, while attempting to control for other factors that might have also influenced crash rates. We used linear regression to estimate the association between the GDL system and the proportion of all crashes that occurred under conditions restricted by the GDL program.

RESULTS

Results showed, contrary to expectations, that rates of crashes during restricted nighttime hours and with passengers were higher among drivers licensed under the updated GDL system. This mirrored a statewide increase in crash rates among drivers of all ages over the study period and likely reflected increased overall driving exposure. The proportions of all crashes that were at night or with passengers did not change. Practical Applications: More research is needed to understand how older novice drivers respond when GDL systems originally designed for younger novice drivers are applied to them.

Burden of disease from transportation noise and motor vehicle crashes: Analysis of data from Houston, Texas

BACKGROUND

Transportation systems have an essential role in satisfying individuals' needs for mobility and accessibility. Yet, they have been linked to several adverse health impacts, with a large, but modifiable, burden of disease. Among the several transportation-related health risk factors, this study focused on transportation-related noise as an emerging exposure whose burden of disease remains partially recognized. We compared premature deaths potentially attributable to transportation-related noise with deaths from motor vehicle crashes, a well-researched and widely recognized transportation risk factor.

METHOD

We employed a standard burden of disease assessment framework to quantify premature cardiovascular diseases mortality attributable to transportation-related (road and aviation) noise at the census tract level (n = 592) in Houston, Texas. The results were compared to motor vehicle crash fatalities, which are routinely observed and collected in the study area. We also investigated the distribution of premature deaths across the city and explored the relationship between household median income and premature deaths attributable to transportation-related noise.

RESULTS

We estimated 302 (95% CI: 185-427) premature deaths (adults 30-75 years old) attributable to transportation-related noise in Houston, compared to 330 fatalities from motor vehicle crashes (adults younger than 75 years old). Transportation-related noise and motor vehicle crashes were responsible for 1.7% and 1.9% of all-cause premature deaths in Houston, respectively. Households with lower median income had a higher risk of adverse exposure and premature deaths potentially attributable to transportation-related noise. A larger number of premature deaths was associated with living in the central business district and the vicinity of highways and airports.

CONCLUSION

This study highlighted the significant contribution of transportation-related noise and motor vehicle crashes to premature deaths in the city of Houston. The analogy between the estimated premature deaths attributable to transportation-related noise and motor vehicle crashes showed that the health impacts of transportation-related noise were as significant as motor vehicle crashes. The estimated premature death rate attributable to transportation-related noise was also comparable to the death rate caused by suicide, influenza, or pneumonia in the US. There is an urgent need for imposing policies to reduce transportation noise emissions and human exposures and to equip health impact assessment tools with a noise burden of disease analysis function.

Public health principles to inform testing and build trust in automated vehicles

Highly publicised crashes involving self-driving or autonomous vehicles (AVs) have raised questions about safety and eroded public trust in the technology. In this State of the Art Review, we draw on previous successes in injury prevention and public health to focus attention on three strategies to reduce risk and build public confidence as AVs are being tested on public roads. Data pooling, a graduated approach to risk exposure, and harm reduction principles each offer practical lessons for AV testing. The review points out how the eventual deployment of AV technology could have a substantial impact on public health. In this regard, inclusive testing, public education and smart policy could extend the social value of AVs by improving access to mobility and by directing deployments towards scenarios with the greatest population health impact. The application of these strategies does not imply slowing down progress; rather, their implementation could accelerate adoption and result in realising the benefits of AVs more quickly and comprehensively while minimising risks.

Prescription opioids, alcohol and fatal motor vehicle crashes: a population-based case-control study

Background

The prevalence of prescription opioid use among drivers has increased markedly in the past two decades. The purpose of this study is to assess the associations of prescription opioid use and alcohol use with the risk of fatal crash involvement in US drivers.

Methods

We performed a population-based case-control study using toxicological testing data from two national data systems. Cases (n = 3606) were drivers involved in fatal motor vehicle crashes selected from the Fatality Analysis Reporting System and controls (n = 15,600) were drivers participating in the 2007 and 2013 National Roadside Surveys of Alcohol and Drug Use by Drivers. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs) of fatal crash involvement associated with prescription opioid use with and without the presence of alcohol.

Results

Overall, cases were significantly more likely than controls to test positive for prescription opioids (5.0% vs. 3.7%, p < 0.001), alcohol (56.2% vs. 7.1%, p < 0.0001), and both substances (2.2% vs. 0.2%, p < 0.001). Relative to drivers testing negative for prescription opioids and alcohol, the adjusted ORs of fatal crash involvement were 1.72 (95% CI: 1.37, 2.17) for those testing positive for prescription opioids and negative for alcohol, 17.92 (95% CI: 16.19, 19.84) for those testing positive for alcohol and negative for prescription opioids, and 21.89 (95% CI: 14.38, 33.32) for those testing positive for both substances. The interaction effect on fatal crash risk of prescription opioid use and alcohol use was not statistically significant on either additive or multiplicative scale.

Conclusions

Prescription opioid use is associated with a significantly increased risk of fatal crash involvement independently of alcohol use. Concurrent use of prescription opioids and alcohol is associated with a 21-fold increased risk of fatal crash involvement.

Characteristics of Single Vehicle Crashes with a Teen Driver in South Carolina, 2005-2008

OBJECTIVE

Teens' crash risk is highest in the first years of independent driving. Circumstances surrounding fatal crashes have been widely documented, but less is known about factors related to nonfatal teen driver crashes. This study describes single vehicle nonfatal crashes involving the youngest teen drivers (15-17 years), compares these crashes to single vehicle nonfatal crashes among adult drivers (35-44 years) and examines factors related to nonfatal injury producing crashes for teen drivers.

METHODS

Police crash data linked to hospital inpatient and emergency department data for 2005-2008 from the South Carolina Crash Outcomes Data Evaluation System (CODES) were analyzed. Nonfatal, single vehicle crashes involving passenger vehicles occurring on public roadways for teen (15-17 years) drivers were compared with those for adult (35-44 years) drivers on temporal patterns and crash risk factors per licensed driver and per vehicle miles traveled. Vehicle miles traveled by age group was estimated using data from the 2009 National Household Travel Survey. Multivariable log-linear regression analysis was conducted for teen driver crashes to determine which characteristics were related to crashes resulting in a minor/moderate injury or serious injury to at least one vehicle occupant.

RESULTS

Compared with adult drivers, teen drivers in South Carolina had 2.5 times the single vehicle nonfatal crash rate per licensed driver and 11 times the rate per vehicle mile traveled. Teen drivers were nearly twice as likely to be speeding at the time of the crash compared with adult drivers. Teen driver crashes per licensed driver were highest during the afternoon hours of 3:00-5:59 pm and crashes per mile driven were highest during the nighttime hours of 9:00-11:59 pm. In 66% of the teen driver crashes, the driver was the only occupant. Crashes were twice as likely to result in serious injury when teen passengers were present than when the teen driver was alone. When teen drivers crashed while transporting teen passengers, the passengers were >5 times more likely to all be restrained if the teen driver was restrained. Crashes in which the teen driver was unrestrained were 80% more likely to result in minor/moderate injury and 6 times more likely to result in serious injury compared with crashes in which the teen driver was restrained.

CONCLUSIONS

Despite the reductions in teen driver crashes associated with Graduated Driver Licensing (GDL), South Carolina's teen driver crash rates remain substantially higher than those for adult drivers. Established risk factors for fatal teen driver crashes, including restraint nonuse, transporting teen passengers, and speeding also increase the risk of nonfatal injury in single vehicle crashes. As South Carolina examines strategies to further reduce teen driver crashes and associated injuries, the state could consider updating its GDL passenger restriction to either none or one passenger <21years and dropping the passenger restriction exemption for trips to and from school. Surveillance systems such as CODES that link crash data with health outcome data provide needed information to more fully understand the circumstances and consequences of teen driver nonfatal crashes and evaluate the effectiveness of strategies to improve teen driver safety.

Police documentation of drug use in injured drivers: Implications for monitoring and preventing drug-impaired driving

INTRODUCTION

Most countries have laws against driving while impaired by drugs. However, in many countries, including Canada and the United States, police must have individualized suspicion that the driver has recently used an impairing substance before they can gather the evidence required for laying a criminal charge. This report studies police documentation of drug involvement among drivers who had a motor-vehicle crash after using an impairing substance.

METHODS

We obtained blood samples and police reports on injured drivers treated in participating British Columbia trauma centres following a crash. Blood was analyzed for alcohol, cannabinoids, other recreational drugs, and impairing medications. Corresponding police reports were examined to determine whether police recorded that the driver's ability was impaired by alcohol, drug or medication, or that one of these substances was a possible contributory factor in the crash.

RESULTS

We obtained blood samples and corresponding police reports on 1816 injured drivers. Mean driver age was 44 years, 63.2% were male, and 25.8% were admitted to hospital. Alcohol was detected in 272 drivers (15.0%), THC (tetrahydrocannabinol - the principal psychoactive ingredient in cannabis) in 136 (7.5%), other recreational drugs in 166 (9.1%), and potentially impairing medications in 363 (20.0%). Police reported that the driver's ability was impaired by alcohol or that alcohol was a possible contributory factor in 64.1% of the crashes involving alcohol-positive drivers. Drug impairment or drugs as a possible contributory factor was reported in 5.9% of the crashes involving THC-positive drivers, and in 16.9% of the crashes involving drivers who tested positive for other recreational drugs. Medication impairment was reported in only 2.2% of the crashes involving medication-positive drivers.

CONCLUSION

Police seldom document drug involvement in drivers who were in a crash after using cannabis, other recreational drugs or potentially impairing medications. This finding raises serious concerns about the ability of the police to effectively enforce current drug-impaired driving laws and public health officials' continued reliance on police crash reports to monitor the prevalence of drug-impaired driving.

The prevalence of seatbelt and mobile phone use among drivers in Riyadh, Saudi Arabia: An observational study

INTRODUCTION

Road traffic injuries (RTIs) are the third leading cause of death in Saudi Arabia. Numerous factors may increase the likelihood of RTIs. The prevalence of risk factors associated with RTIs may vary due to several reasons. Because little is known about these risk factors locally, we examined the prevalence of mobile phone and seatbelt use and their association with spatial locations.

METHODS

This is an observational study conducted at major highways and inner intersections throughout Riyadh, the country's capital. Two observers captured seatbelt and mobile phone use among drivers. Logistic regression models were constructed to examine the association between real estate prices and mobile phone or seatbelt use. Observations were categorized as taken place in an affluent neighborhood if the average price per square meter was above 2500 Saudi Riyal.

RESULTS

A total of 1700 drivers were observed in 13 sites citywide. 13.8% of drivers were seen using mobile while driving and only a third of drivers (34%) were wearing seatbelts. Being at an affluent neighborhood was associated with close to three times higher odds of wearing seatbelts (OR = 2.7, 95% CI = 1.9-3.7) and also associated with 42% lower odds of mobile phone use among drivers (OR = 0.58, 95% CI = 0.36-0.92).

DISCUSSION

This study found a high prevalence of traffic violations among drivers in Riyadh. Based on our estimate, 660,000 drivers are roaming the street during daytime while using their phones and they are less likely to wear seatbelts. Unfortunately, this estimate might contribute to increasing RTIs. Despite existing regulations, seatbelt use among drivers is significantly lower than in developed countries (i.e. USA 94%).

CONCLUSION

Our study found a high prevalence of traffic violations represented by lack of compliance with seatbelt and mobile phone use laws. These findings provide a basis for their underlying prevalence in SA. Practical applications: Public health prevention programs may use these findings to facilitate support to increasing investment in awareness campaigns and further enforcement by the traffic police to reduce RITs and improve population health.

Health outcomes and costs of acute traumatic spinal injury in New South Wales, Australia

BACKGROUND CONTEXT

Traumatic spinal injuries are often associated with both long-term disability, higher frequency of hospital readmissions, and high medical costs for individuals of all ages. Age differences in terms of injury profile and health outcomes among those who sustain a spinal cord injury have been identified. However, factors that may influence health outcomes among those with a spinal injury have not been extensively examined at a population level.

PURPOSE

The present study aims to describe the characteristics of traumatic spinal injury, identify factors predictive of mortality, and estimate the cost of hospital treatment for younger and older people.

STUDY DESIGN/SETTING

This is a population-based retrospective epidemiological study using linked hospitalization and mortality records during January 1, 2010 to June 30, 2014 in New South Wales, Australia.

PATIENT SAMPLE

The present study included 13,429 hospitalizations.

OUTCOME MEASURES

Mortality within 30 and 90 days of hospitalization, hospital length of stay (LOS), and hospitalization costs were determined.

METHODS

Hospitalizations with a principal diagnosis of spinal cord injury or spinal fractures were used to identify traumatic spinal injuries. Age-standardized incidence rates were calculated and negative binomial regression was used to examine statistical significant changes over time. Cox proportional hazard regression was used to examine the effect of risk factors on survival at 90 days.

RESULTS

There were 13,429 hospitalizations, with 52.4% of individuals aged ≥65 years. The hospitalization rates for individuals aged ≤64 and ≥65 years were both estimated to significantly increase per year by 3.3% (95% confidence interval [CI] 0.97-5.79, p<.006) and 3.3% (95% CI 1.02-5.71, p=.005), respectively. For individuals aged ≥65 years, there were a higher proportion of women injured, comorbid conditions, injuries after a fall in the home or aged care facility, a longer hospital LOS, unplanned hospital admissions, and deaths than individual aged ≤64 years. The average cost per index hospitalization was AUD$23,808 for individuals aged ≤64 years and AUD$31,187 for individuals aged ≥65 years with a total estimated cost of AUD$371 million. Mortality risk at 90 days was increased for individuals who had one or more comorbidities, a higher injury severity score, and if their injury occurred in the home or an aged care facility.

CONCLUSIONS

Spinal injury represents a substantial cost and results in debilitating injuries, particularly for older individuals. Spinal injury prevention efforts for older people should focus on the implementation of fall injury prevention, whereas for younger individuals, prevention measures should target road safety.

Fatally injured pedestrians and bicyclists in the United States with high blood alcohol concentrations

INTRODUCTION

Little research has focused on the problem of alcohol impairment among pedestrians and bicyclists in the United States. The aim of the current study was to investigate the prevalence, trends, and characteristics of alcohol-impaired fatally injured pedestrians and bicyclists.

METHOD

Data from the Fatality Analysis Reporting System (FARS) were analyzed for fatally injured passenger vehicle drivers, pedestrians, and bicyclists 16 and older during 1982-2014. Logistic regression models examined whether personal, roadway, and crash characteristics were associated with high blood alcohol concentrations (BACs) among fatally injured pedestrians and bicyclists.

RESULTS

From 1982 to 2014, the percentage of fatally injured pedestrians with high BACs (≥0.08g/dL) declined from 45% to 35%, and the percentage of fatally injured bicyclists with high BACs declined from 28% to 21%. By comparison, the percentage of fatally injured passenger vehicle drivers with high BACs declined from 51% in 1982 to 32% in 2014. The largest reductions in alcohol impairment among fatally injured pedestrians and bicyclists were found among ages 16-20. During 2010-2014, fatally injured pedestrians and bicyclists ages 40-49 had the highest odds of having a high BAC, compared with other age groups.

CONCLUSIONS

A substantial proportion of fatally injured pedestrians and bicyclists have high BACs, and this proportion has declined less dramatically than for fatally injured passenger vehicle drivers during the past three decades. Most countermeasures used to address alcohol-impaired driving may have only limited effectiveness in reducing fatalities among alcohol-impaired pedestrians and bicyclists.

PRACTICAL APPLICATIONS

Efforts should increase public awareness of the risk of walking or bicycling when impaired. Results suggest the primary target audience for educational campaigns directed at pedestrians and bicyclists is middle-age males. Further research should evaluate the effectiveness of potential countermeasures, such as lowering speeds or improving lighting in urban areas.

Awareness of Vision Zero among United States' road safety professionals

Background

Vision Zero is a strategy to eliminate all fatalities and serious injuries from road traffic crashes, while increasing safe and equitable mobility for all. In 2015, the United States’ Department of Transportation announced the official target of the federal government transportation safety policy was zero deaths. In 2017, we assessed the dissemination of Vision Zero in the United States.

Methods

We conducted a web-based survey in 2017 among road safety professionals. Email invitations were sent using relevant membership directories and conference lists.

Results

We surveyed 192 road safety professionals, including planning/engineering (57.8%), public health (16.7%), and law enforcement/emergency medical services (EMS) (8.9%). Awareness of Vision Zero was higher among planning/engineering fields (97.3%) compared to law enforcement/EMS (76.5%) and public health (75.0%). Awareness was similar by number of years working in the field. Awareness was higher in the South (95.9%) and Northeast (95.0%) regions, followed by the West (90.8%) and Midwest (85.2%) Census regions. Among those that heard of Vision Zero (n = 174), 41.8% worked at a municipality with a Vision Zero campaign, while 41.2% did not. Among those working at a municipality with a Vision Zero campaign (n = 71), about half participated in the campaign (54.9%) while the other half did not (45.1%).

Conclusions

With widespread dissemination of the Vision Zero strategy to road safety professionals, next steps include evaluating how Vision Zero is being adopted, implemented, and maintained in communities, as well as the awareness and acceptability by community members, and to identify the most promising policies and practices.

Electronic supplementary material

The online version of this article (10.1186/s40621-018-0151-1) contains supplementary material, which is available to authorized users.

Can Adolescent Drivers' Motor Vehicle Crash Risk Be Reduced by Pre-Licensure Intervention?

PURPOSE

Although motor vehicle crashes are the leading cause of death for adolescents, there is a scarcity of research addressing adolescents' lack of pre-licensure practical driving experience, which is theorized to increase their post-licensure crash risk.

METHODS

Utilizing police-reported crashes and survey data from a randomized and quasi-randomized trial (n = 458 adolescents, 16 or 17 years of age at enrollment), the impact of a parent-directed supervised practice driving intervention and a comprehensive on-road driving assessment (ODA) with feedback was evaluated on adolescent drivers' motor vehicle crashes involvement.

RESULTS

Compared with the control condition, a nonsignificant 20% relative reduction in risk was observed for the parent-directed intervention: adjusted hazard ratio  = .80 (95% confidence interval [CI] .44, 1.43); the unadjusted absolute risk reduction was 1.1% (95% CI -4.4, 7.1). Exposure to the ODA resulted in an 53% relative reduction of risk: adjusted hazard ratio  = .47 (95% CI .24, .91); the unadjusted absolute risk reduction was 5.4% (95% CI -.3, 10.7).

CONCLUSIONS

Comprehensive ODA might be protective for adolescents; however, additional research is needed.

Rage against the machine? Google's self-driving cars versus human drivers

INTRODUCTION

Automated driving represents both challenges and opportunities in highway safety. Google has been developing self-driving cars and testing them under employee supervision on public roads since 2009. These vehicles have been involved in several crashes, and it is of interest how this testing program compares to human drivers in terms of safety.

METHODS

Google car crashes were coded by type and severity based on narratives released by Google. Crash rates per million vehicle miles traveled (VMT) were computed for crashes deemed severe enough to be reportable to police. These were compared with police-reported crash rates for human drivers. Crash types also were compared.

RESULTS

Google cars had a much lower rate of police-reportable crashes per million VMT than human drivers in Mountain View, Calif., during 2009-2015 (2.19 vs 6.06), but the difference was not statistically significant. The most common type of collision involving Google cars was when they got rear-ended by another (human-driven) vehicle. Google cars shared responsibility for only one crash.

CONCLUSIONS

These results suggest Google self-driving cars, while a test program, are safer than conventional human-driven passenger vehicles; however, currently there is insufficient information to fully examine the extent to which disengagements affected these results.

PRACTICAL APPLICATION

Results suggest that highly-automated vehicles can perform more safely than human drivers in certain conditions, but will continue to be involved in crashes with conventionally-driven vehicles.

Graduated driver licensing (GDL) in the United States in 2016: A literature review and commentary

This is the sixth in a series of reviews of research on graduated driver licensing (GDL) published in the Journal of Safety Research, the present review covering the period mid-2012 through 2016. In the two decades since GDL programs began to be introduced on a widespread basis in the United States, a vast amount of research has been published. The current review discusses recent research and the present state of knowledge on the following topics: characteristics of the novice driver population; effects of GDL on crashes for ages 16-19; the learner and intermediate periods; night and passenger restrictions; cellphone laws; GDL for older novices; enforcement of GDL rules; and programs attempting to influence GDL compliance and safe driving practices in general. GDL stands out as a successful policy for reducing teen driver crashes and is worth building on to extend its benefits. Strengthening existing GDL programs has the most potential for producing further crash reductions.

Use of prescription opioids and motor vehicle crashes: A meta analysis

OBJECTIVES

Opioid analgesics are a major driver of the ongoing opioid epidemic in the United Sates, accounting for about two thirds of drug overdose fatalities. There are conflicting reports regarding the effects of prescription opioids on driving safety. A meta-analysis was performed to assess the epidemiologic evidence for the association between use of prescription opioids and the risk of motor vehicle crashes.

METHODS

Studies examining the association between driver prescription opioid use and motor vehicle crash involvement or crash culpability and published in English were identified through a comprehensive search of 15 bibliographic databases. Eligible articles were fully reviewed and summarized. Study quality was assessed using the Newcastle-Ottawa Scale. Overall summary odds ratios (ORs) and 95% confidence intervals (CIs) were estimated through random effects models.

RESULTS

Overall, 15 studies were included in the meta-analysis; of them, 10 assessed the association of prescription opioid use with the risk of crash involvement and 5 assessed the association of prescription opioid use with the risk of crash culpability. Reported crude ORs associated with prescription opioid use ranged from 1.15 to 8.19 for the risk of crash involvement and from 0.75 to 2.78 for the risk of crash culpability. Summary ORs based on pooled data were 2.29 (95% CI: 1.51, 3.48) for crash risk and 1.47 (95% CI: 1.01, 2.13) for crash culpability.

CONCLUSIONS

The existent epidemiologic evidence indicates that use of prescription opioids by drivers is associated with significantly increased risks of crash involvement and crash culpability. Further research is needed to understand the epidemiologic patterns of prescription opioid use in the driver population and the interaction effects between opioids and alcohol on driving safety.

Trends in teen driver licensure, driving patterns and crash involvement in the United States, 2006-2015

INTRODUCTION

The Monitoring the Future (MTF) survey provides nationally-representative annual estimates of licensure and driving patterns among U.S. teens. A previous study using MTF data reported substantial declines in the proportion of high school seniors that were licensed to drive and increases in the proportion of nondrivers following the recent U.S. economic recession.

METHOD

To explore whether licensure and driving patterns among U.S. high school seniors have rebounded in the post-recession years, we analyzed MTF licensure and driving data for the decade of 2006-2015. We also examined trends in teen driver involvement in fatal and nonfatal injury crashes for that decade using data from the Fatality Analysis Reporting System and National Automotive Sampling System General Estimates System, respectively.

RESULTS

During 2006-2015, the proportion of high school seniors that reported having a driver's license declined by 9 percentage points (11%) from 81% to 72% and the proportion that did not drive during an average week increased by 8 percentage points (44%) from 18% to 26%. The annual proportion of black seniors that did not drive was consistently greater than twice the proportion of nondriving white seniors. Overall during the decade, 17- and 18-year-old drivers experienced large declines in fatal and nonfatal injury crashes, although crashes increased in both 2014 and 2015.

CONCLUSIONS

The MTF data indicate that licensure and driving patterns among U.S. high school seniors have not rebounded since the economic recession. The recession had marked negative effects on teen employment opportunities, which likely influenced teen driving patterns. Possible explanations for the apparent discrepancies between the MTF data and the 2014 and 2015 increases in crashes are explored.

PRACTICAL APPLICATIONS

MTF will continue to be an important resource for clarifying teen driving trends in relation to crash trends and informing strategies to improve teen driver safety.

State-level geographic variation in prompt access to care for children after motor vehicle crashes

BACKGROUND

Motor vehicle crashes (MVCs) are a principal cause of death in children; fatal MVCs and pediatric trauma resources vary by state. We sought to examine state-level variability in and predictors of prompt access to care for children in MVCs.

MATERIALS AND METHODS

Using the 2010-2014 Fatality Analysis Reporting System, we identified passengers aged <15 y involved in fatal MVCs (crashes on US public roads with ≥1 death, adult or pediatric, within 30 d). We included children requiring transport for medical care from the crash scene with documented time of hospital arrival. Our primary outcome was transport time to first hospital, defined as >1 or ≤1 h. We used multivariable logistic regression to establish state-level variability in the percentage of children with transport time >1 h, adjusting for injury severity (no injury, possible injury, suspected minor injury, suspected severe injury, fatal injury, and unknown severity), mode of transport (emergency medical services [EMS] air, EMS ground, and non-EMS), and rural roads.

RESULTS

We identified 18,116 children involved in fatal MVCs from 2010 to 2014; 10,407 (57%) required transport for medical care. Median transport time was 1 h (interquartile range: [1, 1]; range: [0, 23]). The percent of children with transport time >1 h varied significantly by state, from 0% in several states to 69% in New Mexico. Children with no injuries identified at the scene and crashes on rural roads were more likely to have transport times >1 h.

CONCLUSIONS

Transport times for children after fatal MVCs varied substantially across states. These results may inform state-level pediatric trauma response planning.

Measuring a conceptual model of the relationship between compulsive cell phone use, in-vehicle cell phone use, and motor vehicle crash

OBJECTIVES

Previous research suggests that anticipation of incoming phone calls or messages and impulsivity are significantly associated with motor vehicle crash. We took a more explanative approach to investigate a conceptual model regarding the direct and indirect effect of compulsive cell phone use and impulsive personality traits on crash risk.

METHODS

We recruited a sample of 307 undergraduate college students to complete an online survey that included measures of cell phone use, impulsivity, and history of motor vehicle crash. Using a structural equation model, we examined the direct and indirect relationships between factors of the Cell Phone Overuse Scale-II (CPOS-II), impulsivity, in-vehicle phone use, and severity and frequency of previous motor vehicle crash. Self-reported miles driven per week and year in college were included as covariates in the model.

RESULTS

Our findings suggest that anticipation of incoming communication has a direct association with greater in-vehicle phone use, but was not directly or indirectly associated with increasing risk of previous motor vehicle crash. Of the three latent factors comprising the CPOS-II, only anticipation was significantly associated with elevated cell phone use while driving. Greater impulsivity and use of in-vehicle cell phone use while driving were directly and significantly associated with greater risk of motor vehicle crash.

CONCLUSIONS

Anticipation of incoming cellular contacts (calls or texts) is associated with greater in-vehicle phone use, while greater in-vehicle cell phone use and impulsive traits are associated with elevated risk of motor vehicle crashes.

"Good Passengers and Not Good Passengers:" Adolescent Drivers' Perceptions About Inattention and Peer Passengers

PURPOSE

The purpose of this qualitative focus group elicitation research study was to explore teen driver perceptions of peer passengers and driver inattention.

DESIGN & METHODS

We utilized focus groups for data collection and content analysis to analyze the data, both of which were guided by the theory of planned behavior. We conducted 7 focus groups with 30 teens, ages 16-18, licensed for ≤1year to examine attitudes, perceived behavioral control, and norms related to driving inattention and peer passengers.

RESULTS

The sample was 50% male, mean age 17.39 (SD 0.52) with mean length of licensure 173.7days (SD 109.2). Three themes emerged: 1) "Good and not good" passengers; 2) Passengers and technology as harmful and helpful; and 3) The driver is in charge.

CONCLUSIONS

While passengers can be a source of distraction, our participants also identified passenger behaviors that reduced risk, such as assistance with technology and guidance for directions.

PRACTICAL IMPLICATIONS

An understanding of teens' perceptions of peer passengers can contribute to the development of effective interventions targeting teen driver inattention. Nurses are well-positioned to contribute to these teen crash prevention efforts.

On-scene factors that predict severe injury of patients involved in frontal crashes of passenger cars

PURPOSE

We sought to determine on-scene factors that predict severe injury to the occupants of passenger cars involved in frontal crashes.

METHODS

From January 2011 to December 2014, we collected data from patients who were taken to two emergency centres following a frontal motor vehicle crash. Binomial logistic regression was used to model the effects of occupant characteristics (sex, age, body mass index), vehicle damage (according to the collision deformation classification code), and safety devices on severe injuries (injury severity score >15).

RESULTS

Of 344 subjects, 75 (21.8 %) had severe injuries. Sex, seat belt status, extent of vertical crash, intrusion, and deformation extent (DE) were significantly different between severe and non-severe injuries. After adjusting for confounders, non-use of seat belt tripled the odds of severe injury [odds ratio (OR) 2.7, 95 % confidence interval (CI) 1.461-5.105]. DE ≥4 and intrusion increased the risk of severe injury (OR 2.4, 95 % CI 1.120-5.204 and OR 5.2, 95 % CI 2.525-10.780, respectively). A combination model to predict severe injury using intrusion, seat belt use, and DE ≥4 demonstrated 56.0 % sensitivity, 88.9 % specificity, and 58.4 % positive predictive value (AUC = 0.781, 95 % CI 0.734-0.824).

CONCLUSIONS

For passenger cars involved in a frontal crash, intrusion, unbelted status, and DE ≥4 are good predictors of severe injury. Sequential criteria using vehicle DE, seat belt use, and intrusion can be used by first responders to triage patients involved in a frontal collision.

Long-term outcomes of individuals injured in motor vehicle crashes: A population-based study

BACKGROUND

Despite decline in U.S. traffic fatalities, non-fatal injuries remain a main cause of reduced self-reported health. The authors used a nationally representative survey to examine the long-term (≥1 year) implications of traffic injuries on self-care, depression, mobility, pain and activity domains of a widely used measure assessing Health-Related Quality of Life (HRQOL).

METHODS

30,576 participants from panels (2000-2002) of the Medical Expenditure Panel Survey (MEPS) were followed for about two years. The associations between reporting a traffic injury in the first follow-up year and the five domains of the Euroqol Health index (EQ-5D) were assessed using mixed logistic models with outcome severe/moderate problem in each domain. Models adjustment variables included age, gender, education, income, diabetes, asthma, smoking and insurance status.

RESULTS

590 participants reported traffic injuries. In the first follow-up analysis, having an injury was associated with deficits in all domains of the EQ-5D. With the exception of self-care, similar findings were reported in the second follow-up (≥1 year) after injuries with strongest associations between traffic injuries and both mobility and activity (both OR=2.9, P<0.01).

CONCLUSIONS

Traffic injuries are significantly associated with long-term reduced HRQOL. Injured individuals may benefit from early intervention programs to prevent the development of secondary complications and reduced HRQOL.

A Review of Hazard Anticipation Training Programs for Young Drivers

PURPOSE

Poor hazard anticipation skills are a risk factor associated with high motor vehicle crash rates of young drivers. A number of programs have been developed to improve these skills. The purpose of this review was to assess the empirical literature on hazard anticipation training for young drivers.

METHODS

Studies were included if they (1) included an assessment of hazard anticipation training outcomes; (2) were published between January 1, 1980 and December 31, 2013 in an English language peer-reviewed journal or conference proceeding; and (3) included at least one group that uniquely comprised a cohort of participants aged <21 years. Nineteen studies met inclusion criteria.

RESULTS

Studies used a variety of training methods including interactive computer programs, videos, simulation, commentary driving, or a combination of approaches. Training effects were predominantly measured through computer-based testing and driving simulation with eye tracking. Four studies included an on-road evaluation. Most studies evaluated short-term outcomes (immediate or few days). In all studies, young drivers showed improvement in selected hazard anticipation outcomes but none investigated crash effects.

CONCLUSIONS

Although there is promise in existing programs, future research should include long-term follow-up, evaluate crash outcomes, and assess the optimal timing of hazard anticipation training taking into account the age and experience level of young drivers.

fatalities among substance-impaired underage youths involved in motor vehicle crashes

INTRODUCTION

Emergency department (ED) visits resulting from motor vehicle crashes (MVCs) among individuals younger than 21 impaired by alcohol and/or drugs have been less studied than MVC fatalities.

METHOD

Using data from 2004 to 2011, we compare the magnitude and pattern of national ED visit and mortality data for alcohol- and drug-impaired youths involved in MVCs.

RESULTS

Temporal patterns of ED visits are similar to those of fatalities, but the two differ in magnitude. The ratio of ED visits to fatalities is 3.5:1; alcohol related events involvement dominates other drugs in both categories.

DISCUSSION

The volume of injuries serious enough to warrant ED visits imposes significant health, social, and financial burdens. In ED visits, alcohol is the prime source of MVC morbidity burden; other drugs consistently contribute less.

PRACTICAL APPLICATIONS

These incidents are persistent and require interventions aimed at multiple levels of prevention, including stricter corrective steps earlier in the impaired driving career to reduce subsequent incidents. ED visits for MVC injuries can be important "teachable moments." Limitations of the study indicate the need for improved surveillance of underage substance-involved crashes.

Factors associated with mortality in rear-seated adult passengers involved in fatal motor vehicle crashes on US roadways

BACKGROUND

Recent efforts to pass rear seat belt laws for adults have been hampered by large gaps in the scientific literature. This study examines driver, vehicle, crash, and passenger characteristics associated with mortality in rear-seated adult passengers.

METHODS

The Fatality Analysis Reporting System (FARS) 2010 to 2011 was used to examine motor vehicle occupant mortality in rear-seated adult passengers 18 years and older. Side crash vehicle safety ratings were assessed in a subset analysis of vehicles struck on the same side as the rear-seated passenger. Multilevel logistic regression models used SAS GLIMMIX.

RESULTS

Of the 7,229 rear-seated adult passengers, 2,091 (28.9%) died. Multivariable predictors of increased mortality were advancing passenger age, younger driver age, excessive speed, ejection, being unbelted, rear impact, and same-side crash. Belt use was associated with a 67.0% reduction in total mortality. Despite this, belt wearing was low (48.1%) and differed by seating position, with less than one third of middle-seated passengers belted. Multivariable analysis showed mortality to be nearly three times higher in same-side crashes than other impact locations (odds ratio (OR) = 2.76, 2.22, 3.44). In a multivariable subpopulation analysis of same-side crashes, right-seated passengers had an increased mortality (52.7% vs. 43.2%, p < 0.01) compared to left-seated passengers (OR = 1.55, 1.02, 2.36). Vehicle side crash safety ratings, available for 27.7% (n = 172) of same-side crashes, were not predictive of mortality.

CONCLUSIONS

Except for same-side crashes, seat belts were associated with significantly lowered mortality. Despite this, seat belt wearing was low and represents one of several areas where further improvements in mortality might be realized.

Age, period, and cohort effects in motor vehicle mortality in the United States, 1980-2010: the role of sex, alcohol involvement, and position in vehicle

INTRODUCTION

Although substantive declines in motor vehicle fatalities in 1980-2010 have been observed, declines by position in the vehicle and alcohol involvement have not been well elucidated.

METHOD

Analyses of FARS data use the Intrinsic Estimator (IE) to produce estimates of all age, period, and cohort effects simultaneously by position in the car and by alcohol involvement.

RESULTS

Declines in MVC deaths by position in the car vary for men and women by age and cohort over time. Cohorts born before 1970 had higher risks than those born later. Analyses using proxy indicators of alcohol involvement found the highest risks for those aged 16-24. By period, these risks declined more rapidly than non- alcohol related traffic fatalities.

CONCLUSION

Changes in risk patterns are consistent with evidence regarding the contributions of new technologies and public policy efforts to reduce fatalities, but gains have not been shared evenly by sex or position in the car.

PRACTICAL APPLICATIONS

Greater attention is needed in reducing deaths among older drivers and pedestrians. Gender differences should be addressed in prevention efforts aimed at reducing MVCs due to alcohol involvement.

Modelling total duration of traffic incidents including incident detection and recovery time

Traffic incidents are key contributors to non-recurrent congestion, potentially generating significant delay. Factors that influence the duration of incidents are important to understand so that effective mitigation strategies can be implemented. To identify and quantify the effects of influential factors, a methodology for studying total incident duration based on historical data from an 'integrated database' is proposed. Incident duration models are developed using a selected freeway segment in the Southeast Queensland, Australia network. The models include incident detection and recovery time as components of incident duration. A hazard-based duration modelling approach is applied to model incident duration as a function of a variety of factors that influence traffic incident duration. Parametric accelerated failure time survival models are developed to capture heterogeneity as a function of explanatory variables, with both fixed and random parameters specifications. The analysis reveals that factors affecting incident duration include incident characteristics (severity, type, injury, medical requirements, etc.), infrastructure characteristics (roadway shoulder availability), time of day, and traffic characteristics. The results indicate that event type durations are uniquely different, thus requiring different responses to effectively clear them. Furthermore, the results highlight the presence of unobserved incident duration heterogeneity as captured by the random parameter models, suggesting that additional factors need to be considered in future modelling efforts.