The impact of texting bans on motor vehicle crash-related hospitalizations

Implications of using administrative healthcare data to identify risk of motor vehicle crash-related injury: the importance of distinguishing crash from crash-related injury

BACKGROUND

Administrative healthcare databases, such as Medicare, are increasingly used to identify groups at risk of a crash. However, they only contain information on crash-related injuries, not all crashes. If the driver characteristics associated with crash and crash-related injury differ, conflating the two may result in ineffective or imprecise policy interventions.

METHODS

We linked 10 years (2008-2017) of Medicare claims to New Jersey police crash reports to compare the demographics, clinical diagnoses, and prescription drug dispensings for crash-involved drivers ≥ 68 years with a police-reported crash to those with a claim for a crash-related injury. We calculated standardized mean differences to compare characteristics between groups.

RESULTS

Crash-involved drivers with a Medicare claim for an injury were more likely than those with a police-reported crash to be female (62.4% vs. 51.8%, standardized mean difference [SMD] = 0.30), had more clinical diagnoses including Alzheimer's disease and related dementias (13.0% vs. 9.2%, SMD = 0.20) and rheumatoid arthritis/osteoarthritis (69.5% vs 61.4%, SMD = 0.20), and a higher rate of dispensing for opioids (33.8% vs 27.6%, SMD = 0.18) and antiepileptics (12.9% vs 9.6%, SMD = 0.14) prior to the crash. Despite documented inconsistencies in coding practices, findings were robust when restricted to claims indicating the injured party was the driver or was left unspecified.

CONCLUSIONS

To identify effective mechanisms for reducing morbidity and mortality from crashes, researchers should consider augmenting administrative datasets with information from police crash reports, and vice versa. When those data are not available, we caution researchers and policymakers against the tendency to conflate crash and crash-related injury when interpreting their findings.

Major Traffic Safety Reform and Road Traffic Injuries Among Low-Income New York Residents, 2009-2021

Objectives. To evaluate the effects of a comprehensive traffic safety policy-New York City's (NYC's) 2014 Vision Zero-on the health of Medicaid enrollees. Methods. We conducted difference-in-differences analyses using individual-level New York Medicaid data to measure traffic injuries and expenditures from 2009 to 2021, comparing NYC to surrounding counties without traffic reforms (n = 65 585 568 person-years). Results. After Vision Zero, injury rates among NYC Medicaid enrollees diverged from those of surrounding counties, with a net impact of 77.5 fewer injuries per 100 000 person-years annually (95% confidence interval = -97.4, -57.6). We observed marked reductions in severe injuries (brain injury, hospitalizations) and savings of $90.8 million in Medicaid expenditures over the first 5 years. Effects were largest among Black residents. Impacts were reversed during the COVID-19 period. Conclusions. Vision Zero resulted in substantial protection for socioeconomically disadvantaged populations known to face heightened risk of injury, but the policy's effectiveness decreased during the pandemic period. Public Health Implications. Many cities have recently launched Vision Zero policies and others plan to do so. This research adds to the evidence on how and in what circumstances comprehensive traffic policies protect public health. (Am J Public Health. 2024;114(6):633-641. https://doi.org/10.2105/AJPH.2024.307617).

A systematic review of the evidence for effectiveness of interventions to address transport and other unintentional injuries among adolescents

INTRODUCTION

Globally, injuries are a leading cause of mortality and morbidity for adolescents, which disproportionately affect the disadvantaged. To build an investment case for adolescent injury prevention, evidence is needed as to effective interventions.

METHODS

A systematic review of peer-reviewed original research published between 2010-2022 was conducted. CINAHL, Cochrane Central, Embase, Medline and PsycINFO databases were searched for studies reporting the effectiveness of unintentional injury prevention interventions for adolescents (10-24 years), with assessment of study quality and equity (e.g., age, gender, ethnicity, socio-economic status).

RESULTS

Sixty-two studies were included; 59 (95.2%) from high-income countries (HIC). Thirty-eight studies (61.3%) reported no aspect of equity. Thirty-six studies (58.1%) reported prevention of sports injuries (commonly neuromuscular training often focused on soccer-related injuries, rule changes and protective equipment). Twenty-one studies (33.9%) reported prevention of road traffic injury, with legislative approaches, commonly graduated driver licensing schemes, found to be effective in reducing fatal and nonfatal road traffic injury. Seven studies reported interventions for other unintentional injuries (e.g., falls).

DISCUSSION

Interventions were strongly biased towards HIC, which does not reflect the global distribution of adolescent injury burden. Low consideration of equity in included studies indicates current evidence largely excludes adolescent populations at increased risk of injury. A large proportion of studies evaluated interventions to prevent sports injury, a prevalent yet low severity injury mechanism. Findings highlight the importance of education and enforcement alongside legislative approaches for preventing adolescent transport injuries. Despite drowning being a leading cause of injury-related harm among adolescents, no interventions were identified.

CONCLUSION

This review provides evidence to support investment in effective adolescent injury prevention interventions. Further evidence of effectiveness is needed, especially for low- and middle-income countries, populations at increased risk of injury who would benefit from greater consideration of equity and for high lethality injury mechanisms like drowning.

Cost-benefit analysis of a distracted pedestrian intervention

OBJECTIVE

Cellphone ubiquity has increased distracted pedestrian behaviour and contributed to growing pedestrian injury rates. A major barrier to large-scale implementation of prevention programmes is unavailable information on potential monetary benefits. We evaluated net economic societal benefits of StreetBit, a programme that reduces distracted pedestrian behaviour by sending warnings from intersection-installed Bluetooth beacons to distracted pedestrians' smartphones.

METHODS

Three data sources were used as follows: (1) fatal, severe, non-severe pedestrian injury rates from Alabama's electronic crash reporting system; (2) expected costs per fatal, severe, non-severe pedestrian injury-including medical cost, value of statistical life, work-loss cost, quality-of-life cost-from CDC and (3) prevalence of distracted walking from extant literature. We computed and compared estimated monetary costs of distracted walking in Alabama and monetary benefits from implementing StreetBit to reduce pedestrian injuries at intersections.

RESULTS

Over 2019-2021, Alabama recorded an annual average of 31 fatal, 83 severe and 115 non-severe pedestrian injuries in intersections. Expected costs/injury were US$11 million, US$339 535 and US$93 877, respectively. The estimated distracted walking prevalence is 25%-40%, and StreetBit demonstrates 19.1% (95% CI 1.6% to 36.0%) reduction. These figures demonstrate potential annual cost savings from using interventions like StreetBit statewide ranging from US$18.1 to US$29 million. Potential costs range from US$3 208 600 (beacons at every-fourth urban intersection) to US$6 359 200 (every other intersection).

CONCLUSIONS

Even under the most parsimonious scenario (25% distracted pedestrians; densest beacon placement), StreetBit yields US$11.8 million estimated net annual benefit to society. Existing data sources can be leveraged to predict net monetary benefits of distracted pedestrian interventions like StreetBit and facilitate large-scale intervention adoption.

Cortical and subcortical response to the anticipation of reward in high and average/low risk-taking adolescents

Since the first neurodevelopmental models that sought to explain the influx of risky behaviors during adolescence were proposed, there have been a number of revisions, variations and criticisms. Despite providing a strong multi-disciplinary heuristic to explain the development of risk behavior, extant models have not yet reliably isolated neural systems that underlie risk behaviors in adolescence. To address this gap, we screened 2017 adolescents from an ongoing longitudinal study that assessed 15-health risk behaviors, targeting 104 adolescents (Age Range: 17-to-21.4), characterized as high-or-average/low risk-taking. Participants completed the Monetary Incentive Delay (MID) fMRI task, examining reward anticipation to "big win" versus "neutral". We examined neural response variation associated with both baseline and longitudinal (multi-wave) risk classifications. Analyses included examination of a priori regions of interest (ROIs); and exploratory non-parametric, whole-brain analyses. Hypothesis-driven ROI analysis revealed no significant differences between high- and average/low-risk profiles using either baseline or multi-wave classification. Results of whole-brain analyses differed according to whether risk assessment was based on baseline or multi-wave data. Despite significant mean-level task activation, these results do not generalize prior neural substrates implicated in reward anticipation and adolescent risk-taking. Further, these data indicate that whole-brain differences may depend on how risk-behavior profiles are defined.

Evaluating the impact of penalising the use of mobile phones while driving on road traffic fatalities, serious injuries and mobile phone use: a systematic review

BACKGROUND

A vast literature has demonstrated that using mobile phones while driving increases the risk of road traffic crashes. In response, policy-makers have introduced bans and harsher penalties on using mobile phones while driving. Even though emerging evidence suggests that such measures may reduce mobile phone use and crashes, the literature has not been systematically reviewed and synthesised.

OBJECTIVE

To evaluate the impact of penalising mobile phone use while driving on road traffic fatalities, serious injuries and the prevalence of mobile phone use while driving.

METHODS

We employed a comprehensive search strategy using electronic databases, websites, handsearching and other sources to locate studies evaluating legislation on mobile phone use while driving. Randomised controlled trials, interrupted time series', controlled before-after studies with control(s) not exposed to harsher sanctions and panel data designs were included if they measured the outcomes of fatalities, serious injuries or the prevalence of mobile phone use while driving. Eligible studies were critically appraised. Due to substantial heterogeneity, the results were synthesised narratively. The synthesis structured studies according to the type of legislation and outcome measure.

RESULTS

Of the 7420 studies retrieved, 32 were included. The evidence on the effects of penalising mobile phone use while driving was weak, and somewhat inconsistent, but pointed to a potential decrease in the prevalence of mobile phone use and fatalities for all-driver primary enforcement hand-held bans and texting bans.

CONCLUSIONS

Preventing fatalities from risky driving practices may be helped by implementing harsher laws that penalise mobile phone use while driving.

Preventing injuries must be a priority to prevent disease in the twenty-first century

Injuries continue to be the leading cause of morbidity and mortality for children, adolescents, and young adults aged 1-24 years in industrialized countries in the twenty-first century. In this age group, injuries cause more fatalities than all other causes combined in the United States (U.S.). Importantly, many of these injuries are preventable. Annually in the U.S. there are >9 million emergency department visits for injuries and >16,000 deaths in children and adolescents aged 0-19 years. Among injury mechanisms, motor vehicle crashes, firearm suicide, and firearm homicide remain the leading mechanisms of injury-related death. More recently, poisoning has become a rapidly rising cause of both intentional and unintentional death in teenagers and young adults aged 15-24 years. For young children aged 1-5 years, water submersion injuries are the leading cause of death. Sports and home-related injuries are important mechanisms of nonfatal injuries. Preventing injuries, which potentially cause lifelong morbidity, as well as preventing injury deaths, must be a priority. A multi-pronged approach using legislation, advancing safety technology, improving the built environment, anticipatory guidance by clinical providers, and education of caregivers will be necessary to decrease and prevent injuries in the twenty-first century.

Heads Up, Phones Down: A Pedestrian Safety Intervention on Distracted Crosswalk Behavior

Cell phone use has been implicated in driver distraction and motor vehicle crashes, and more recently has been associated with distracted pedestrians. There are limited data on interventions aimed at this important public health issue. We hypothesized that the use of a visual intervention near street crossings would decrease the frequency of distracted behaviors of pedestrians. We performed a prospective observational cohort study examining painted sidewalk stencils reading, "Heads Up, Phones Down" as an intervention to decrease cell phone distractions amongst pedestrians. These stenciled messages were placed at a children's hospital, middle school, and high school in Los Angeles County. Anonymous observations of pedestrian distractions (texting, talking on a phone, headphone use, and other) were conducted before, 1 week after, and 4 months after the intervention. Distractions were compared before and after intervention using Chi square tests. A total of 11,533 pedestrians were observed, with 71% children and 29% adults. Total distractions decreased from 23% pre-intervention to 17% 1 week after stencil placement (p < 0.01), but this was not sustained at 4 months (23%, p = 0.4). A sustained decrease was observed only for texting at 4 months post-intervention (8.5% vs. 6.8%, p < 0.01). A simple visual intervention reduced distracted cell phone usage in pedestrians crossing the street, but this was most effective early after the intervention. Future studies are warranted to determine how to sustain this effect over time and how to minimize other types of distractions.

A Behavioral Economic Analysis of Demand for Texting while Driving

The overarching goal of the present study was to determine whether a behavioral economic framework of demand analysis is applicable to texting while driving. To this end, we developed a novel hypothetical task designed to quantify the intensity and elasticity of the demand for social interaction from texting while driving. This task involved a scenario in which participants receive a text message while driving, and they rated the likelihood of replying to a text message immediately versus waiting to reply until arriving at a destination when the amounts of a fine for texting while driving ranged from $1 to $300. To assess the construct validity of the task, the scenario presented two delays to a destination (15 min and 60 min). The demand for social interaction from texting was more intense (greater at the lowest amount of the fine) and less elastic (less sensitive to the increase in the amounts of the fine) for drivers who self-reported a higher frequency of texting while driving than for those who self-reported a lower frequency of texting while driving. Demand was also more intense and less elastic under the 60-min delay condition than under the 15-min condition. The results of this proof-of-concept study suggest that behavioral economic demand analyses are potentially useful for understanding and predicting texting while driving.

Texting-While-Driving Bans and Motor Vehicle Crash-Related Emergency Department Visits in 16 US States: 2007-2014

OBJECTIVES

To examine the impact of state texting bans on motor vehicle crash (MVC)-related emergency department (ED) visits.

METHODS

We used ED data from 16 US states between 2007 and 2014. We employed a difference-in-difference approach and conditional Poisson regressions to estimate changes in counts of MVC-related ED visits in states with and without texting bans. We also constructed age cohorts to explore whether texting bans have differential impacts by age group.

RESULTS

On average, states with a texting ban saw a 4% reduction in MVC-related ED visits (incidence rate ratio = 0.96; 95% confidence interval = 0.96, 0.97). This equates to an average of 1632 traffic-related ED visits prevented per year in states with a ban. Both primary and secondary bans were associated with significant reductions in MVC-related visits to the ED regardless of whether they were on all drivers or young drivers only. Individuals aged 64 years and younger in states with a texting ban saw significantly fewer MVC-related ED visits following its implementation.

CONCLUSIONS

Our findings suggest that states' efforts to curb distracted driving through texting bans and decrease its negative consequences are associated with significant decreases in the incidence of ED visits that follow an MVC.

Threat appeals reduce impulsive decision making associated with texting while driving: A behavioral economic approach

The primary purpose of the present study was to examine the effectiveness of threat appeals in influencing impulsive decision making associated with texting while driving. The participants in the treatment group were exposed to a threatening message about the danger of texting while driving, whereas those in the control group were exposed to a non-threatening message. Following the exposure to either message, the participants completed a delay-discounting task that assessed the degree of impulsive decision making in a hypothetical texting-while-driving scenario. A comparison between the groups revealed that the threat appeals reduced the degree of impulsive decision making associated with texting while driving. In addition, the threat appeals led to greater anticipated regret from texting while driving, less favorable attitudes toward texting while driving, and decreased intentions to text while driving in the future in the treatment group. These results suggest that video-based threat appeals are promising intervention strategies for the public health challenge of texting while driving. Implications from the behavioral economic perspective are discussed.

Adolescents' perspectives on distracted driving legislation

PURPOSE

Distracted driving is a growing global epidemic, with adolescent drivers reporting frequent engagement in distracted driving behaviors. Public health initiatives and legislative efforts designed to decrease the prevalence of these unwanted driving behaviors have demonstrated small, but significant reductions in crash risk. Non-compliance is a known problem among drivers of all ages, but may be especially problematic for novice, adolescent drivers. Using a construct from the Health Belief Model, the relations between demographic factors, perceived threat to safety, and peer influences were investigated with adolescents' support for three types of distracted driving legislation regarding: (a) reading or sending text messages/emails while driving; (b) hand-held cell phone use while driving; and (c) using non-driving-related-in-vehicle (NDIV) technology while driving. Investigating adolescents' perceptions provides an opportunity to understand distracted driving enforcement and legislation.

METHODS

Three hundred and seventy-nine adolescents aged 15-19 (M = 16.12, SD = 0.56) were recruited from public high schools. Demographics, perceptions, and support regarding distracted driving were assessed using self-report surveys. Statistical analyses included bivariate correlations and adjusted odds ratios to investigate influences of adolescent support for distracted driving legislation.

RESULTS

Female adolescents were at 2 times greater odds of supporting a law against texting/emailing while driving compared to male adolescents. Greater perceived threat to safety was associated with all three types of distracted driving legislation (aOR = 1.10, 1.33). Minimal association was found with peer influences.

CONCLUSIONS

Perceived threat to safety and gender were associated with legislative support in adolescents. Practical application: Interventions and public health campaigns that incorporate elements related to perceived threat may be more successful with female adolescent drivers than male adolescents. Future experimental research will help to determine what factors affect adolescents' perspectives on distracted driving to promote compliance with related legislation.

The Teen Driver

For many teenagers, obtaining a driver's license is a rite of passage, conferring the ability to independently travel to school, work, or social events. However, immaturity, inexperience, and risky behavior put newly licensed teen drivers at risk. Motor vehicle crashes are the most common cause of mortality and injury for adolescents and young adults in developed countries. Teen drivers (15-19 years of age) have the highest rate of motor vehicle crashes among all age groups in the United States and contribute disproportionately to traffic fatalities. In addition to the deaths of teen drivers, more than half of 8- to 17-year-old children who die in car crashes are killed as passengers of drivers younger than 20 years of age. This policy statement, in which we update the previous 2006 iteration of this policy statement, is used to reflect new research on the risks faced by teen drivers and offer advice for pediatricians counseling teen drivers and their families.

Cell phone use while driving laws and motor vehicle driver fatalities: differences in population subgroups and location

PURPOSE

Research suggests that cell phone use while driving laws are associated with lower driver fatalities. This study seeks to determine whether this relationship is modified by driver age (16-24, 25-39, 40-59, ≥60), sex (male, female), race/ethnicity (white non-Hispanic, white Hispanic, black non-Hispanic, other), or rurality (rural, urban).

METHODS

Fatality Analysis Reporting System data were merged with state legislation (2000-2014). The exposure was the type of legislation in effect. The outcome was non-alcohol-related driver fatalities by state-quarter-year. Incident rate ratios were estimated using generalized Poisson mixed regression for overdispersed count data with robust standard errors.

RESULTS

Amongst 190,544 drivers, compared to periods without bans, universal hand-held calling bans were associated with 10% (adjusted incident rate ratio = 0.90, 95% confidence interval 0.84, 0.96) lower non-alcohol-related driver fatalities overall and up to 13% lower fatalities across all age groups and sexes but not for race/ethnicity or rurality. When comparing state-quarter-years with bans to those without, universal texting bans were not associated with lower fatalities overall or for any demographic group.

CONCLUSIONS

The relationships between cell phone laws and non-alcohol-related driver fatalities are modified by driver demographics, particularly for universal hand-held bans. Universal hand-held calling bans may benefit more types of drivers compared to texting bans.

The roles of delay and probability discounting in texting while driving: Toward the development of a translational scientific program

A sample of 109 college students completed a survey to assess how frequently they send or read text messages while driving. In a novel discounting task with a hypothetical scenario in which participants receive a text message while driving, they rated the likelihood of replying to a text message immediately versus waiting to reply until arriving at a destination. The scenario presented several delays to a destination and probabilities of a motor vehicle crash. The likelihood of waiting to reply decreased as a function of both the delay until the destination and the probability of a motor vehicle crash. Self-reported higher frequencies of texting while driving were associated with greater rates of both delay and probability discounting. The degree of delay discounting was altered as a function of the probability of a motor vehicle crash and vice versa. These results suggest that both delay and probability discounting are important underlying mechanisms of drivers' decision to text while driving.

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.

Texting while driving: the development and validation of the distracted driving survey and risk score among young adults

BACKGROUND

Texting while driving and other cell-phone reading and writing activities are high-risk activities associated with motor vehicle collisions and mortality. This paper describes the development and preliminary evaluation of the Distracted Driving Survey (DDS) and score.

METHODS

Survey questions were developed by a research team using semi-structured interviews, pilot-tested, and evaluated in young drivers for validity and reliability. Questions focused on texting while driving and use of email, social media, and maps on cellular phones with specific questions about the driving speeds at which these activities are performed.

RESULTS

In 228 drivers 18-24 years old, the DDS showed excellent internal consistency (Cronbach's alpha = 0.93) and correlations with reported 12-month crash rates. The score is reported on a 0-44 scale with 44 being highest risk behaviors. For every 1 unit increase of the DDS score, the odds of reporting a car crash increases 7 %. The survey can be completed in two minutes, or less than five minutes if demographic and background information is included. Text messaging was common; 59.2 and 71.5 % of respondents said they wrote and read text messages, respectively, while driving in the last 30 days.

CONCLUSION

The DDS is an 11-item scale that measures cell phone-related distracted driving risk and includes reading/viewing and writing subscores. The scale demonstrated strong validity and reliability in drivers age 24 and younger. The DDS may be useful for measuring rates of cell-phone related distracted driving and for evaluating public health interventions focused on reducing such behaviors.

Trends in cell phone use among children in the Danish national birth cohort at ages 7 and 11 years

We prospectively examined trends in cell phone use among children in the Danish National Birth Cohort. Cell phone use was assessed at ages 7 and 11 years, and we examined use patterns by age, by year of birth, and in relation to specific individual characteristics. There was an increase in cell phone use from age 7 (37%) to 11 years (94%). There was a clear pattern of greater reported cell phone use among children at age 7 years with later birth year, but this trend disappeared at age 11. Girls and those who used phones at age 7 talked more often and for longer durations at age 11 years. Low socio-economic status and later year of birth were associated with voice calls at age 7 but not at age 11 years. At age 11 most used cell phones for texting and gaming more than for voice calls. Further, children who started using cell phones at age 7 years were more likely to be heavy cell phone voice users at age 11 years, making early use a marker for higher cumulative exposure regardless of year of birth. As cell phone technology continues to advance, new use patterns will continue to emerge, and exposure assessment research among children must reflect these trends.

Adolescent Cellphone Use While Driving: An Overview of the Literature and Promising Future Directions for Prevention

Motor vehicle crashes are the leading cause of death in adolescents, and drivers aged 16-19 are the most likely to die in distracted driving crashes. This paper provides an overview of the literature on adolescent cellphone use while driving, focusing on the crash risk, incidence, risk factors for engagement, and the effectiveness of current mitigation strategies. We conclude by discussing promising future approaches to prevent crashes related to cellphone use in adolescents. Handheld manipulation of the phone while driving has been shown to have a 3 to 4-fold increased risk of a near crash or crash, and eye glance duration greater than 2 seconds increases crash risk exponentially. Nearly half of U.S. high school students admit to texting while driving in the last month, but the frequency of use according to vehicle speed and high-risk situations remains unknown. Several risk factors are associated with cell phone use while driving including: parental cellphone use while driving, social norms for quick responses to text messages, and higher levels of temporal discounting. Given the limited effectiveness of current mitigation strategies such as educational campaigns and legal bans, a multi-pronged behavioral and technological approach addressing the above risk factors will be necessary to reduce this dangerous behavior in adolescents.

Driving through the Great Recession: Why does motor vehicle fatality decrease when the economy slows down?

The relationship between short-term macroeconomic growth and temporary mortality increases remains strongest for motor vehicle (MV) crashes. In this paper, I investigate the mechanisms that explain falling MV fatality rates during the recent Great Recession. Using U.S. state-level panel data from 2003 to 2013, I first estimate the relationship between unemployment and MV fatality rate and then decompose it into risk and exposure factors for different types of MV crashes. Results reveal a significant 2.9 percent decrease in MV fatality rate for each percentage point increase in unemployment rate. This relationship is almost entirely explained by changes in the risk of driving rather than exposure to the amount of driving and is particularly robust for crashes involving large commercial trucks, multiple vehicles, and speeding cars. These findings provide evidence suggesting traffic patterns directly related to economic activity lead to higher risk of MV fatality rates when the economy improves.

Safety-critical event risk associated with cell phone tasks as measured in naturalistic driving studies: A systematic review and meta-analysis

A systematic review and meta-analysis of naturalistic driving studies involving estimates of safety-critical event risk associated with handheld device use while driving is described. Fifty-seven studies identified from targeted databases, journals and websites were reviewed in depth, and six were ultimately included. These six studies, published between 2006 and 2014, encompass seven sets of naturalistic driver data and describe original research that utilized naturalistic methods to assess the effects of distracting behaviors. Four studies involved non-commercial drivers of light vehicles and two studies involved commercial drivers of trucks and buses. Odds ratios quantifying safety-critical event (SCE) risk associated with talking, dialing, locating or answering, and texting or browsing were extracted. Stratified meta-analysis of pooled odds ratios was used to estimate SCE risk by distraction type; meta-regression was used to test for sources of heterogeneity. The results indicate that tasks that require drivers to take their eyes off the road, such as dialing, locating a phone and texting, increase SCE risk to a greater extent than tasks that do not require eyes off the road such as talking. Although talking on a handheld device did not increase SCE risk, further research is required to determine whether it indirectly influences SCE risk (e.g., by encouraging other cell phone activities). In addition, a number of study biases and quality issues of naturalistic driving studies are discussed.