Traffic safety in the U.S.: re-examining major opportunities

Mobility management to prevent, reduce, or delay driving a car in teenagers

BACKGROUND

Rates of injury and death caused by car crashes with teenage drivers remain high in most high-income countries. In addition to injury and death, car use includes other non-traffic risks; these may be health-related, such as physical inactivity or respiratory disease caused by air pollution, or have global significance, such as the environmental impact of car use. Research demonstrates that reducing the amount of time driving reduces the risk of injury, and it is expected that it would also reduce other risks that are unrelated to traffic. Mobility management interventions aim to increase mobility awareness and encourage a shift from private car use to active (walking, cycling, skateboarding), and public (bus, tram, train), transportation. 'Soft' mobility management interventions include the application of strategies and policies to reduce travel demand and may be instigated locally or more widely, to target a specific or a non-specific population group; 'hard' mobility management interventions include changes to the built environment or transport infrastructure and are not the focus of this review. Between the ages of 15 to 19 years, young people enter a development stage known as the 'transition teens' in which they are likely to make long-lasting lifestyle changes. It is possible that using this specific time point to introduce mobility management interventions may influence a person's long-term mobility behaviour.

OBJECTIVES

To assess whether 'soft' mobility management interventions prevent, reduce, or delay car driving in teenagers aged 15 to 19 years, and to assess whether these mobility management interventions also reduce crashes caused by teenage drivers.

SEARCH METHODS

We searched the Cochrane Injuries Group Specialised Register, CENTRAL, MEDLINE, Embase, Web of Science, and Social Policy and Practice on 16 August 2019. We searched clinical trials registers, relevant conference proceedings, and online media sources of transport organisations, and conducted backward- and forward-citation searching of relevant articles.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or controlled before-after studies (CBAs) evaluating mobility management interventions in teenagers aged 15 to 19 years. We included informational, educational, or behavioural interventions that aimed to prevent, reduce, or delay car driving in this age group, and we compared these interventions with no intervention or with standard practice. We excluded studies that evaluated graduated drivers licensing (GDL) programmes, separate components of GDL, or interventions that act in conjunction with, or as an extension of, GDL. Such programmes aim to increase driving experience and skills through stages of supervised and unsupervised exposure, but assume that all participants will drive; they do not attempt to encourage people to drive less in the long term or promote alternatives to driving. We also excluded studies which evaluated school-based safe-driving initiatives.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, and assessed risks of bias. We assessed the certainty of evidence with GRADE.

MAIN RESULTS

We included one RCT with 178 participants and one CBA with 860 participants. The RCT allocated university students, with a mean age of 18 years, who had not yet acquired a driving licence, to one of four interventions that provided educational information about negative aspects of car use, or to a fifth group in which no information was given. Types of educational information about car use related to cost, risk, or stress, or all three types of educational information combined. In the CBA, 860 school students, aged 17 to 18 years taking a driving theory course, had an additional interactive lesson about active transport (walking or cycling), and some were invited to join a relevant Facebook group with posts targeting awareness and habit. We did not conduct meta-analyses because we had insufficient studies. We could not be certain whether educational interventions versus no information affected people's decision to obtain a driving licence 18 months after receiving the intervention (risk ratio 0.62, 95% confidence interval 0.45 to 0.85; very low-certainty evidence). We noted that fewer participants who were given information obtained a driving licence (42.6%) compared to those who did not receive information (69%), but we had very little confidence in the effect estimate; the study had high or unclear risks of bias and the evidence was from one small study and was therefore imprecise. We could not be certain whether interventions about active transport, given during a driving theory course, could influence behavioural predictors of car use. Study authors noted: - an increased intention to use active transport after obtaining a driving licence between postintervention and an eight-week follow-up in students who were given an active transport lesson and a Facebook invitation compared to those given only the active transport lesson; and - a decrease in intention between pre- and postintervention in those given an active transport lesson and Facebook invitation compared to those given the active transport lesson only. There were high risks of bias in this CBA study design, a large amount of missing data (very few participants accepted the Facebook invitation), and data came from a single study only, so we judged the evidence to be of very low certainty. These studies did not measure our primary outcome (driving frequency), or other secondary outcomes (driving distance, driving hours, use of alternative modes of transport, or car crashes).

AUTHORS' CONCLUSIONS

We found only two small studies, and could not determine whether mobility management interventions were effective to prevent, reduce, or delay car driving in teenagers. The lack of evidence in this review raises two points. First, more foundational research is needed to discover how and why young people make decisions surrounding their personal transport, in order to find out what might encourage them to delay licensing and driving. Second, we need longitudinal studies with a robust study design - such as RCTs - and with large sample sizes that incorporate different socioeconomic groups in order to evaluate the feasibility and effectiveness of relevant interventions. Ideally, evaluations will include an assessment of how attitudes and beliefs evolve in teenagers during these transition years, and the potential effect of these on the design of a mobility management intervention for this age group.

The Use of Telematics Devices to Improve Automobile Insurance Rates

Most automobile insurance databases contain a large number of policyholders with zero claims. This high frequency of zeros may reflect the fact that some insureds make little use of their vehicle, or that they do not wish to make a claim for small accidents in order to avoid an increase in their premium, but it might also be because of good driving. We analyze information on exposure to risk and driving habits using telematics data from a pay-as-you-drive sample of insureds. We include distance traveled per year as part of an offset in a zero-inflated Poisson model to predict the excess of zeros. We show the existence of a learning effect for large values of distance traveled, so that longer driving should result in higher premiums, but there should be a discount for drivers who accumulate longer distances over time due to the increased proportion of zero claims. We confirm that speed limit violations and driving in urban areas increase the expected number of accident claims. We discuss how telematics information can be used to design better insurance and to improve traffic safety.

The conspicuity of pedestrians at night: a review

Drivers' visual limitations are a leading contributor to night-time traffic crashes involving pedestrians. This paper reviews the basic changes in vision that occur at night for young and old visually healthy drivers, as well as those with common ocular pathology. To maximise their safety at night, pedestrians should be conspicuous. That is, beyond being simply visible (detectable as an ambiguous object), they should attract the attention of drivers and be readily perceivable as pedestrians. Research has established that the conspicuity of pedestrians can be optimised by attaching retroreflective markings to the pedestrian's extremities. Doing so highlights the pedestrian's 'biological motion,' which facilitates the accurate perception of a person; however, retroreflective markings on the torso (for example, vests) are less effective. Importantly, behavioural evidence indicates that most road users - drivers and pedestrians alike - are not aware of the limitations of night vision. For example, drivers typically 'overdrive' the useful range of their headlight beams and under-use their high beam headlight setting. Further, pedestrians overestimate their own conspicuity at night and fail to appreciate the extent to which their own conspicuity depends on their clothing. The widespread misunderstanding of the challenges associated with night driving reflects a lack of awareness of the fundamental limitations of night vision. Educational interventions are needed to ameliorate these dangerous misunderstandings and to improve the safety of all road users at night.

Observers’ Judgments of the Effects of Glare on Their Visual Acuity for High and Low Contrast Stimuli

Disability glare refers to a reduction in the ability to discern a stimulus that is positioned near another stimulus that has a much higher luminance. While it is common for drivers to report that they have been “blinded” by oncoming headlights, it is unclear whether observers can accurately judge when they are visually disabled by glare. This experiment sought to quantify the accuracy with which observers can judge when a glare source reduces their visual acuity. Seventeen observers estimated their disability glare threshold (DGT)—the luminance of a glare source that would be just sufficient to impair their ability to discern the orientation of a Landolt C that was surrounded by the glare source. These estimated DGTs were compared to the participant’s actual DGTs. Participants consistently underestimated the intensity of glare that was required to impair their acuity. On average, estimates of glare threshold were 88% lower than actual glare threshold intensities. Participants’ judgments were affected by stimulus size but not stimulus contrast. These results suggest that observers can exaggerate the debilitating effects of glare and that they can fail to appreciate that high contrast stimuli are more robust to glare. A driver who believes that even the lowest intensities of headlight glare can visually impair an oncoming driver may be reluctant to use high beam headlamps, despite their significant visibility advantages.

Time and distance to first accident and driving patterns of young drivers with pay-as-you-drive insurance

We conducted a study of approximately 16,000 drivers under the age of 30 that had purchased a pay-as-you-drive insurance policy, where their risk of being involved in a crash was analyzed from vehicle tracking data using a global positioning system. The comparison of novice vs. experienced young drivers shows that vehicle usage differs significantly between these groups and that the time to the first crash is shorter for those drivers with less experience. Driving at night and a higher proportion of speed limit violations reduces the time to the first crash for both novice and experienced young drivers, while urban driving reduces the distance traveled to the first crash for both groups. Gender differences are also observed in relation to the influence of driving patterns on the risk of accident. Nighttime driving reduces the time to the first accident in the case of women, but not for men. The risk of an accident increases with excessive speed, but the effect of speed is significantly higher for men than it is for women among the more experienced drivers.

The effect of traffic tickets on road traffic crashes

Road traffic crashes are globally a leading cause of death. The current study tests the effect of traffic tickets issued to drivers on subsequent crashes, using a unique dataset that overcomes some shortcomings of previous studies. The study takes advantage of a national longitudinal dataset at the individual level that merges Israeli census data with data on traffic tickets issued by the police and official data on involvement in road traffic crashes over seven years. The results show that the estimated probability of involvement in a subsequent fatal or severe crash was more than eleven times higher for drivers with six traffic tickets per year compared to those with one ticket per year, while controlling for various confounders. However, the majority of fatal and severe crashes involved the larger population of drivers who received up to one ticket on average per year. The current findings indicate that reducing traffic violations may contribute significantly to crash and injury reduction. In addition, mass random enforcement programs may be more effective in reducing fatal and severe crashes than targeting high-risk recidivist drivers.

Pedestrians' estimates of their own nighttime conspicuity are unaffected by severe reductions in headlight illumination

INTRODUCTION

At night pedestrians tend to overestimate their conspicuity to oncoming drivers, but little is known about factors affecting pedestrians' conspicuity estimates. This study examines how headlamp intensity and pedestrians' clothing influence judgments of their own conspicuity.

METHOD

Forty-eight undergraduate students estimated their own conspicuity on an unilluminated closed road by walking in front of a stationary vehicle to the point at which they judged that they were just recognizable to the driver. Unknown to the participants, high beam intensity was manipulated between subjects by placing neutral density filters on the headlamps.

RESULTS

Estimated conspicuity distances did not significantly vary with changes in headlamp intensity even when only 3% of the illumination from the headlamps was present.

PRACTICAL APPLICATIONS

These findings underscore the need to educate pedestrians about the visual challenges that drivers face at night and the need to minimize pedestrians' exposure to traffic flow at night.

Driving citations: relationships with criminal behavior

OBJECTIVE

The purpose of the present study was to examine relationships, if any, between the number of lifetime driving citations and the number of lifetime criminal charges.

METHODS

Using a cross-sectional, consecutive sample of internal medicine outpatients and a self-report survey methodology, we queried participants about the number of past driving citations as well as charges for any of 27 criminal behaviors as delineated by the crime cataloguing schema of the Federal Bureau of Investigation.

RESULTS

Scores on the measure of driving citations were positively correlated with scores on the measure of different forms of illegal behavior (r = .39, p < .001). Additional analyses indicated that the relationship between driving citations and illegal behaviors did not vary by sex.

CONCLUSIONS

Though the receipt of driving citations is fairly common, an increasing number of driving citations demonstrates a relationship with criminal behavior. This relationship may be mediated by a number of psychological variables, including various Axis I and II disorders.

Effects of Pay-As-You-Drive vehicle insurance on young drivers' speed choice: results of a Dutch field experiment

Speeding is an important cause for young drivers' involvement in traffic accidents. A reduction in driving speeds of this group could result in fewer accidents. One way of reducing driving speed is offering explicit financial incentives. In collaboration with five Dutch car insurance companies, we tested the effects of a Pay-As-You-Drive insurance fee on driving speed. A group of young drivers could save money on their monthly insurance fee by keeping the speed limit. Driving speed was monitored through GPS technology during one year. Analyses showed that, relative to pre- and post-measurement, as well as a control group, the introduction of a Pay-As-You-Drive insurance fee significantly reduced speed violations of young drivers.

Fatal crash trends for Australian young drivers 1997-2007: geographic and socioeconomic differentials

BACKGROUND

Little has been published on changes in young driver fatality rates over time. This paper examines differences in Australian young driver fatality rates over the last decade, examining important risk factors including place of residence and socioeconomic status (SES).

METHODS

Young driver (17-25years) police-recorded passenger vehicle crashes were extracted from New South Wales State records from 1997-2007. Rurality of residence and SES were classified into three levels based on drivers' residential postcode: urban, regional, or rural; and high, moderate, or low SES areas. Geographic and SES disparities in trends of fatality rates were examined by the generalized linear model. Chi-square trend test was used to examine the distributions of posted speed limits, drinking driving, fatigue, seatbelt use, vehicle age, night-time driving, and the time from crash to death across rurality and socioeconomic status.

RESULTS

Young driver fatality rate significantly decreased 5% per year (p<0.05); however, stratified analyses (by rurality and by SES) showed that only the reduction among urban drivers was significant (average 5% decrease per year, p<0.01). The higher relative risk of fatality for rural versus urban drivers, and for drivers of low versus high SES remained unchanged over the last decade. High posted speed limits, fatigue, drink driving and seatbelt non-use were significantly associated with rural fatalities, whereas high posted speed limit, fatigue, and driving an older vehicle were significantly related to low SES fatality.

CONCLUSION

The constant geographic and SES disparities in young driver fatality rates highlight safety inequities for those living in rural areas and those of low SES. Better targeted interventions are needed, including attention to behavioral risk factors and vehicle age.

Primary access to vehicles increases risky teen driving behaviors and crashes: national perspective

OBJECTIVE

The goal was to explore teen driver vehicle access and its association with risky driving behaviors and crashes.

METHODS

A nationally representative, school-based survey of 2167 ninth-, 10th-, and 11th-graders examined patterns of vehicle access (primary access [ie, the teen is the main driver of the vehicle] versus shared access) and associated driving exposure, risky driving behaviors, and sociodemographic factors.

RESULTS

Seventy percent of drivers reported having primary access to vehicles. They were more likely to be white, to be in 11th grade, to attend schools with higher socioeconomic levels, to have mostly A/B grades, to have a job, to drive a pickup truck, and to drive more hours per week but were not more or less likely to consume alcohol or to wear seat belts while driving. Compared with drivers with shared access, drivers with primary access reported more than twice the crash risk (risk ratio [RR]: 2.05 [95% confidence interval [CI]: 1.41-2.99]) and higher likelihoods of using cellular telephones while driving (RR: 1.23 [95% CI: 1.12-1.35]) and speeding> or =10 mph above the posted limit (RR: 1.24 [95% CI: 1.11-1.40]).

CONCLUSIONS

Primary access of novice teen drivers to vehicles is highly prevalent in the United States. This practice is a dangerous norm, because primary access is associated with risky driving behaviors. Healthcare providers and schools should consider counseling parents to discourage giving novice teen drivers primary access to vehicles. In communities where teens require primary access (eg, due to limited public transportation options), greater efforts should be made to promote safe behaviors.

Seeing pedestrians at night: visual clutter does not mask biological motion

Although placing reflective markers on pedestrians' major joints can make pedestrians more conspicuous to drivers at night, it has been suggested that this "biological motion" effect may be reduced when visual clutter is present. We tested whether extraneous points of light affected the ability of 12 younger and 12 older drivers to see pedestrians as they drove on a closed road at night. Pedestrians wore black clothing alone or with retroreflective markings in four different configurations. One pedestrian walked in place and was surrounded by clutter on half of the trials. Another was always surrounded by visual clutter but either walked in place or stood still. Clothing configuration, pedestrian motion, and driver age influenced conspicuity but clutter did not. The results confirm that even in the presence of visual clutter pedestrians wearing biological motion configurations are recognized more often and at greater distances than when they wear a reflective vest.

A model for preventing serious traffic injury in teens: or "keep those teenagers out of our ICU!"

Traffic crashes are the leading cause of injury, disability, and death in the youth of the United States. Risky driving, behind-the-wheel behaviors when operating a motor vehicle in a manner that may lead to harm or injury to oneself or others, contributes to the human and economic cost of risky driving. An acute or critical care hospitalization provides an ideal opportunity for nurses to initiate prevention strategies with parents and teens to reduce risky driving.

The relationship between blood alcohol concentration (BAC), age, and crash risk

PROBLEM

The role of age (youth and driving inexperience) and alcohol as major risk factors in traffic crash causation has been firmly established by numerous studies over the past 50 years. Less well established is how the two variables interrelate to influence crash risk. Some investigations have hypothesized an interactive or synergistic effect in which young drivers with less experience and a greater tendency to take risks are more adversely affected at lower blood alcohol concentrations (BACs) than are older drivers. The evidence for this hypothesis is mixed. Resolution of this issue has important implication for developing countermeasures directed at the young driver crash problem.

METHOD

Case control data previously collected in Long Beach and Fort Lauderdale were reanalyzed using a more sensitive method for detecting interaction effects than used in the original analysis. A conditional logistic regression analyses found a highly significant agexBAC interaction (P<.0001) involving differences between drivers under 21 and those 21 and older.

DISCUSSION

The results clearly indicate that positive BACs in drivers under 21 are associated with higher relative crash risks than would be predicted from the additive effect of BAC and age. It is likely that two mechanisms are operating to cause the interaction. First, it seems likely that the crash avoidance skill of young novice drivers would be more adversely affected by alcohol due to their driving inexperience, immaturity, and less experience with alcohol. Second, drivers under 21 who choose to drink and to drive after drinking probably have pre-existing characteristics that predisposed them to risk taking and crash involvement apart from any increased vulnerability to alcohol impairment.

IMPACT ON INDUSTRY

The results support increased enforcement of zero-tolerance BAC laws for minors.