Neural processes during adolescent risky decision making are associated with conformity to peer influence.

Adolescents demonstrate both heightened sensitivity to peer influence and increased risk-taking. The current study provides a novel test of how these two phenomena are related at behavioral and neural levels. Adolescent males (N = 83, 16-17 years) completed the Balloon Analogue Risk Task (BART) in an fMRI scanner. One week later, participants completed a driving task in which they drove alone and with a safety- or risk-promoting peer passenger. Results showed that neural responses during BART were associated with participants' behavioral conformity to safe vs. risky peer influence while later driving. First, the extent that neural activation in the anterior cingulate cortex (ACC) scaled with decision stakes in BART was associated with conformity to risky peer influence. Additionally, stake-modulated functional connectivity between ventral striatum (VS) and risk processing regions (including ACC and insula) was associated with safer driving under risky peer influence (i.e. resistance to risky peer influence), suggesting that connectivity between VS and ACC as well as insula may serve a protective role under risky peer influence. Together, these results suggest that adolescents' neural responses to risky decision making may modulate their behavioral conformity to different types of peer influence on risk taking.

The Effect of Teenage Passengers on Simulated Risky Driving Among Teenagers: A Randomized Trial.

Teenage passengers might influence risky driving, particularly in certain mental states. Notably, social exclusion could increase social conformity. Two studies examined simulated intersection management among young drivers after a social exclusion activity (Cyberball). In Study 1 [112 males (mean = 17.3 years)], risky driving was significantly greater among excluded males driving with a risk-accepting vs. passive passenger; no effect of social exclusion. In Study 2 [115 females (mean = 17.1 years)], risky driving was significantly greater among excluded females driving with a risk-accepting vs. a passive passenger, and greater among those included (fair play) vs. excluded when driving with a risk-accepting passenger. Risky driving behavior among male and female teenagers may be influenced uniquely by passenger norms and social exclusion.

Spatial variation in teens' crash rate reduction following the implementation of a graduated driver licensing program in Michigan.

Motor vehicle crashes are a leading cause of injury, and teen drivers contribute disproportionately to that burden. Graduated Driver Licensing (GDL) programs are effective at reducing teen crash risk, but teen crash rates remain high. Between-state variation in the teen crash rate reduction following GDL implementation has been documented, but this is the first study to examine small-area variation in such a reduction. Fusing together crash data from the Michigan State Police, census data, and organizational data (alcohol outlet, movie theatre, and school locations), we analyzed spatial correlates of teen injury crash, and place-based features that modified the injury crash rate difference following GDL implementation. Specifically, using census-based units, we estimated changes in injury crash rates among teens using negative binomial regression controlling for spatial autocorrelation, and tested whether any measured spatial characteristics modified the crash rate change in the pre versus post GDL periods. There was a substantial reduction in teen crashes after GDL implementation (RR = 0.66, 95%CI: [0.65, 0.67]), and this effect was robust across gender and time-of-day (light/dark). We found evidence that this reduction varied across space; areas with more alcohol outlets corresponded to a larger daytime crash rate reduction post-GDL, while areas near schools corresponded to a smaller daytime crash rate reduction. Concentrations of movie theatres corresponded to larger post-GDL crash rate reductions after dark. Maximizing the substantial successes of GDL programs requires understanding why crash rate reductions were larger in some areas following GDL implementation, and harnessing that understanding to improve its effectiveness across a state, focusing on identifying priorities for improving driver training (e.g., by parents and driver educators), law enforcement, and future policy changes to current GDL laws.

Design and implementation of a parent guide for coaching teen drivers.

INTRODUCTION: Teens beginning to drive independently are at significant increased risk of motor-vehicle crashes relative to their other life stages. There is, however, little guidance for parents as to how best to supervise learning to drive. METHOD: This study sought to undertake an informed approach to development and implementation of a Parent Guide. We included a multi-stage development process, using theory, findings from a Delphi-study of young driver traffic-safety experts, and parent focus groups. This process informed the development of a Guide that was then evaluated for feasibility and acceptability, comparing a group that received the Guide with a control group of parent and teen dyads. Both members of the dyads were surveyed at baseline, again at the approximate time teens would be licensed to drive independently (post-test), and again three months later. RESULTS: We found no difference in the proportion of teens who became licensed between those given the new Guide and control teens (who received the state-developed booklet); that is the Guide did not appear to promote or delay licensure. Teens in the Guide group reported that their parents were more likely to use the provided resource compared with control teens. Responses indicated that the Parent Guide was favorably viewed, that it was easy to use, and that the logging of hours was a useful inclusion. Parents noted that the Guide helped them manage their stress, provided strategies to keep calm, and helped with planning practice. In contrast, control parents noted that their booklet helped explain rules. Among licensed teens there was no significant difference in self-reported risky driving at the three-month follow-up. We discuss the challenges in providing motivation for parents to move beyond a set number of practice hours to provide diversity of driving practice.

Peer Passenger Norms and Pressure: Experimental Effects on Simulated Driving Among Teenage Males.

OBJECTIVE: Serious crashes are more likely when teenage drivers have teenage passengers. One likely source of this increased risk is social influences on driving performance. This driving simulator study experimentally tested the effects of peer influence (i.e., risk-accepting compared to risk-averse peer norms reinforced by pressure) on the driving risk behavior (i.e., risky driving behavior and inattention to hazards) of male teenagers. It was hypothesized that peer presence would result in greater driving risk behavior (i.e., increased driving risk and reduced latent hazard anticipation), and that the effect would be greater when the peer was risk-accepting. METHODS: Fifty-three 16- and 17-year-old male participants holding a provisional U.S., State of Michigan driver license were randomized to either a risk-accepting or risk-averse condition. Each participant operated a driving simulator while alone and separately with a confederate peer passenger. The simulator world included scenarios designed to elicit variation in driving risk behavior with a teen passenger present in the vehicle. RESULTS: Significant interactions of passenger presence (passenger present vs. alone) by risk condition (risk-accepting vs. risk-averse) were observed for variables measuring: failure to stop at yellow light intersections (Incident Rate Ratio (IRR)=2.16; 95% Confidence Interval [95CI]=1.06, 4.43); higher probability of overtaking (IRR=10.17; 95CI=1.43, 73.35); shorter left turn latency (IRR=0.43; 95CI=0.31,0.60); and, failure to stop at an intersection with an occluded stop sign (IRR=7.90; 95CI=2.06,30.35). In all cases, greater risky driving by participants was more likely with a risk-accepting passenger versus a risk-averse passenger present and a risk-accepting passenger present versus driving alone. CONCLUSIONS: Exposure of male teenagers to a risk-accepting confederate peer passenger who applied peer influence increased simulated risky driving behavior compared with exposure to a risk-averse confederate peer passenger or driving alone. These results are consistent with the contention that variability in teenage risky driving is in part explained by social influences.

Translation to Primary Care of an Effective Teen Safe Driving Program for Parents.

Addressing teen driver crashes, this study adapted an effective Checkpoints(TM) program for parents of teen drivers for dissemination by primary care practitioners (PCPs) and the web; distributed the PCP/web program through pediatric practices; and examined dissemination to/implementation by parents. The website, youngDRIVERparenting.org, and brief intervention protocol were developed. PCPs delivered interventions and materials to parents, referred them to the website, and completed follow-up surveys. Google Analytics assessed parents' website use. Most PCPs reported delivering interventions with fidelity, and thought the program important and feasible. Brief interventions/website referrals, averaging 4.4 minutes, were delivered to 3465 (87%) of 3990 eligible parents by 133 PCPs over an 18-week average. Website visits (1453) were made by 42% of parents, who spent on average 3:53 minutes viewing 4.2 topics. This program costs little (its website, training and promotional materials are available) and could be one component of a comprehensive approach to reducing teen driver crashes.

Do as I say, not as I do: Distracted driving behavior of teens and their parents.

INTRODUCTION: Driver distraction is an important contributor to crash risk. Teenage driver distraction can be influenced by the attitudes and behaviors of parents. This study examined teens' and their parents' engagement in distracting behavior while driving. METHOD: Survey data were collected from a national sample of 403 parent-teen dyads using random-digit dialing telephone interviews. RESULTS: Results demonstrated few parent or teen sex differences in distracting behavior engagement while driving, or in their perceptions of each others' behavior. Parents and teens' frequencies of distracting behavior engagement were positively correlated. Parents' and teens' perceptions of each others' distracting behavior engagement while driving exceeded their own selfreports. Finally, the likelihood that teens reported engaging in distracting behavior while driving was more strongly associated with their perceptions of their parents' distracting behavior than by parents' self reports of their own behavior. CONCLUSIONS: These results suggest that parents' examples of driving behavior are an important influence on teen driving behavior, but potentially more important are teens' perceptions of their parents' behaviors.

Buffering social influence: neural correlates of response inhibition predict driving safety in the presence of a peer.

Adolescence is a period characterized by increased sensitivity to social cues, as well as increased risk-taking in the presence of peers. For example, automobile crashes are the leading cause of death for adolescents, and driving with peers increases the risk of a fatal crash. Growing evidence points to an interaction between neural systems implicated in cognitive control and social and emotional context in predicting adolescent risk. We tested such a relationship in recently licensed teen drivers. Participants completed an fMRI session in which neural activity was measured during a response inhibition task, followed by a separate driving simulator session 1 week later. Participants drove alone and with a peer who was randomly assigned to express risk-promoting or risk-averse social norms. The experimentally manipulated social context during the simulated drive moderated the relationship between individual differences in neural activity in the hypothesized cognitive control network (right inferior frontal gyrus, BG) and risk-taking in the driving context a week later. Increased activity in the response inhibition network was not associated with risk-taking in the presence of a risky peer but was significantly predictive of safer driving in the presence of a cautious peer, above and beyond self-reported susceptibility to peer pressure. Individual differences in recruitment of the response inhibition network may allow those with stronger inhibitory control to override risky tendencies when in the presence of cautious peers. This relationship between social context and individual differences in brain function expands our understanding of neural systems involved in top-down cognitive control during adolescent development.

Quantifying the influence of safe road systems and legal licensing age on road mortality among young adolescents: steps towards system thinking.

Based on existing literature, a system thinking approach was used to set up a conceptual model on the interrelationships among the components influencing adolescent road mortality, distinguishing between components at the individual level and at the system level. At the individual level the role of risk behaviour (sometimes deliberate and sometimes from inexperience or other non-deliberate causes) in adolescent road mortality is well documented. However, little is known about the extent to which the 'road system' itself may also have an impact on younger adolescents' road mortality. This, by providing a safe or unsafe road environment for all road users (System-induced exposure) and by allowing access to high-risk vehicles at a young or older age through the legal licensing age. This study seeks to explore these relationships by analysing the extent to which the road mortality of 10 to 17 year olds in various jurisdictions can be predicted from the System-induced Exposure (SiE) in a jurisdiction and from its legal licensing age to drive motor vehicles. SiE was operationalized as the number of road fatalities per 10(5) inhabitants/all ages together, but excluding the 10 to 17 year olds. Data on road fatalities during the years 2001 through 2008 were obtained from the OECD International Road Traffic Accident Database (IRTAD) and from the USA NHTSA's Fatality Analysis Reporting System (FARS) database for 29 early and 10 late licensing jurisdictions. Linear mixed models were fitted with annual 'Adolescent road mortality per capita' for 2001 through 2008 as the dependent variable, and time-dependent 'SiE' and time-independent 'Licensing system' as predictor variables. To control for different levels of motorisation, the time-dependent variable 'Annual per capita vehicle distance travelled' was used as a covariate. Licensing system of a jurisdiction was entered as a categorical predictor variable with late licensing countries as a baseline group. The study found support for the protective effects of SiE on adolescent safety. If SiE increased by one unit, the mortality rate of 10 to 17 year olds increased by 0.487 units. No support was found for a protective effect of late licensing for this age group. Thus, compared to young adolescents who are allowed to drive motor vehicles in early licensing jurisdictions, late licensing does not provide extra protection for pre-license adolescents. This finding is probably the result of the high risks associated with alternative transport modes, such as moped riding and bicycling. Also, the fact that the study only included risks to young adolescents themselves and did not include the risks they might pose to other road users and passengers may have contributed to this finding, because such risks are greater when driving a motor vehicle than riding a moped or a bicycle. Therefore, to advance our understanding of the impact of licensing systems, more study is needed into the benefits of early or late licensing, thereby considering these wider effects as well.

Neural responses to exclusion predict susceptibility to social influence.

PURPOSE: Social influence is prominent across the lifespan, but sensitivity to influence is especially high during adolescence and is often associated with increased risk taking. Such risk taking can have dire consequences. For example, in American adolescents, traffic-related crashes are leading causes of nonfatal injury and death. Neural measures may be especially useful in understanding the basic mechanisms of adolescents' vulnerability to peer influence. METHODS: We examined neural responses to social exclusion as potential predictors of risk taking in the presence of peers in recently licensed adolescent drivers. Risk taking was assessed in a driving simulator session occurring approximately 1 week after the neuroimaging session. RESULTS: Increased activity in neural systems associated with the distress of social exclusion and mentalizing during an exclusion episode predicted increased risk taking in the presence of a peer (controlling for solo risk behavior) during a driving simulator session outside the neuroimaging laboratory 1 week later. These neural measures predicted risky driving behavior above and beyond self-reports of susceptibility to peer pressure and distress during exclusion. CONCLUSIONS: These results address the neural bases of social influence and risk taking; contribute to our understanding of social and emotional function in the adolescent brain; and link neural activity in specific, hypothesized, regions to risk-relevant outcomes beyond the neuroimaging laboratory. Results of this investigation are discussed in terms of the mechanisms underlying risk taking in adolescents and the public health implications for adolescent driving.

Social norms and risk perception: predictors of distracted driving behavior among novice adolescent drivers.

PURPOSE: Adolescent drivers are at elevated crash risk due to distracted driving behavior (DDB). Understanding parental and peer influences on adolescent DDB may aid future efforts to decrease crash risk. We examined the influence of risk perception, sensation seeking, as well as descriptive and injunctive social norms on adolescent DDB using the theory of normative social behavior. METHODS: 403 adolescents (aged 16-18 years) and their parents were surveyed by telephone. Survey instruments measured self-reported sociodemographics, DDB, sensation seeking, risk perception, descriptive norms (perceived parent DDB, parent self-reported DDB, and perceived peer DDB), and injunctive norms (parent approval of DDB and peer approval of DDB). Hierarchical multiple linear regression was used to predict the influence of descriptive and injunctive social norms, risk perception, and sensation seeking on adolescent DDB. RESULTS: 92% of adolescents reported regularly engaging in DDB. Adolescents perceived that their parents and peers participated in DDB more frequently than themselves. Adolescent risk perception, parent DDB, perceived parent DDB, and perceived peer DDB were predictive of adolescent DDB in the regression model, but parent approval and peer approval of DDB were not predictive. Risk perception and parental DDB were stronger predictors among males, whereas perceived parental DDB was stronger for female adolescents. CONCLUSIONS: Adolescent risk perception and descriptive norms are important predictors of adolescent distracted driving. More study is needed to understand the role of injunctive normative influences on adolescent DDB. Effective public health interventions should address parental role modeling, parental monitoring of adolescent driving, and social marketing techniques that correct misconceptions of norms related to around driver distraction and crash risk.

Peer passenger influences on male adolescent drivers' visual scanning behavior during simulated driving.

PURPOSE: There is a higher likelihood of crashes and fatalities when an adolescent drives with peer passengers, especially for male drivers and male passengers. Simulated driving of male adolescent drivers with male peer passengers was studied to examine passenger influences on distraction and inattention. METHODS: Male adolescents drove in a high-fidelity driving simulator with a male confederate who posed either as a risk-accepting passenger or as a risk-averse passenger. Drivers' eye movements were recorded. The visual scanning behavior of the drivers was compared when driving alone with when driving with a passenger and when driving with a risk-accepting passenger with a risk-averse passenger. RESULTS: The visual scanning of a driver significantly narrowed horizontally and vertically when driving with a peer passenger. There were no significant differences in the times the drivers' eyes were off the forward roadway when driving with a passenger versus when driving alone. Some significant correlations were found between personality characteristics and the outcome measures. CONCLUSIONS: The presence of a male peer passenger was associated with a reduction in the visual scanning range of male adolescent drivers. This reduction could be a result of potential cognitive load imposed on the driver due to the presence of a passenger and the real or perceived normative influences or expectations from the passenger.

Five road safety education programmes for young adolescent pedestrians and cyclists: a multi-programme evaluation in a field setting.

A practical approach was developed to assess and compare the effects of five short road safety education (RSE) programmes for young adolescents that does not rely on injury or crash data but uses self reported behaviour. Questionnaires were administered just before and about one month after participation in the RSE programmes, both to youngsters who had participated in a RSE programme, the intervention group, and to a comparable reference group of youngsters who had not, the reference group. For each RSE programme, the answers to the questionnaires in the pre- and post-test were checked for internal consistency and then condensed into a single safety score using categorical principal components analysis. Next, an analysis of covariance was performed on the obtained safety scores in order to compare the post-test scores of the intervention and reference groups, corrected for their corresponding pre-test scores. It was found that three out of five RSE programmes resulted in significantly improved self-reported safety behaviour. However, the proportions of participants that changed their behaviour relative to the reference group were small, ranging from 3% to 20%. Comparisons among programme types showed cognitive approaches not to differ in effect from programmes that used fear-appeal approaches. The method used provides a useful tool to assess and compare the effects of different education programmes on self-reported behaviour.

Experimental effects of injunctive norms on simulated risky driving among teenage males.

OBJECTIVE: Teenage passengers affect teenage driving performance, possibly by social influence. To examine the effect of social norms on driving behavior, male teenagers were randomly assigned to drive in a simulator with a peer-aged confederate to whom participants were primed to attribute either risk-accepting or risk-averse social norms. It was hypothesized that teenage drivers would engage in more risky driving behavior in the presence of peer passengers than no passengers, and with a risk-accepting compared with a risk-averse passenger. METHOD: 66 male participants aged 16 to 18 years holding a provisional driver license were randomized to drive with a risk-accepting or risk-averse passenger in a simulator. Failure to Stop at a red light and percent Time in Red (light) were measured as primary risk-relevant outcomes of interest at 18 intersections, while driving once alone and once with their assigned passenger. RESULTS: The effect of passenger presence on risky driving was moderated by passenger type for Failed to Stop in a generalized linear mixed model (OR = 1.84, 95% CI [1.19, 2.86], p < .001), and percent Time in Red in a mixed model (B = 7.71, 95% CI [1.54, 13.87], p < .05). CONCLUSIONS: Exposure of teenage males to a risk-accepting confederate peer increased teenage males' risky simulated driving behavior compared with exposure to a risk-averse confederate peer. These results indicate that variability in teenage risky driving could be partially explained by social norms.

The effect of the learner license Graduated Driver Licensing components on teen drivers' crashes.

BACKGROUND: Most studies evaluating the effectiveness of Graduated Driver Licensing (GDL) have focused on the overall system. Studies examining individual components have rarely accounted for the confounding of multiple, simultaneously implemented components. The purpose of this paper is to quantify the effects of a required learner license duration and required hours of supervised driving on teen driver fatal crashes. METHODS: States that introduced a single GDL component independent of any other during the period 1990-2009 were identified. Monthly and quarterly fatal crash rates per 100,000 population of 16- and 17-year-old drivers were analyzed using single-state time series analysis, adjusting for adult crash rates and gasoline prices. Using the parameter estimates from each state's time series model, the pooled effect of each GDL component on 16- and 17-year-old drivers' fatal crashes was estimated using a random effects meta-analytic model to combine findings across states. RESULTS: In three states, a six-month minimum learner license duration was associated with a significant decline in combined 16- and 17-year-old drivers' fatal crash rates. The pooled effect of the minimum learner license duration across all states in the sample was associated with a significant change in combined 16- and 17-year-old driver fatal crash rates of -.07 (95% Confidence Interval [CI] -.11, -.03). Following the introduction of 30 h of required supervised driving in one state, novice drivers' fatal crash rates increased 35%. The pooled effect across all states in the study sample of having a supervised driving hour requirement was not significantly different from zero (.04, 95% CI -.15, .22). CONCLUSION: These findings suggest that a learner license duration of at least six-months may be necessary to achieve a significant decline in teen drivers' fatal crash rates. Evidence of the effect of required hours of supervised driving on teen drivers' fatal crash rates was mixed.

Dating violence: outcomes following a brief motivational interviewing intervention among at-risk adolescents in an urban emergency department.

OBJECTIVES: A recent study demonstrated the efficacy of the SafERteens intervention in reducing peer violence among adolescents presenting to the emergency department (ED). The objective of this study was to determine the efficacy of this ED-based brief intervention (BI) on dating violence 1 year following the ED visit among the subsample of adolescents in the original randomized controlled trial reporting past-year dating violence. METHODS: Patients (aged 14 to 18 years) at an ED were eligible for inclusion if they had past-year violence and alcohol use. Participants were randomized to one of three conditions (BI delivered by a computer [CBI], BI delivered by a therapist and a computer (T+CBI), or control) and completed follow-ups at 3, 6, and 12 months. In addition to content on alcohol misuse and peer violence, adolescents reporting dating violence received a tailored module on dating violence. The outcome of interest was frequency of moderate and severe dating violence victimization and aggression (baseline and 3, 6, and 12 months after ED visit). RESULTS: Among eligible adolescents, 55% (n = 397) reported dating violence and were included in these analyses. Compared to the control group (who received a resource brochure only), participants in the CBI showed reductions in moderate dating victimization at 3 months (inter-rater reliability [IRR] = 0.71; 95% confidence interval [CI] = 0.51 to 0.99; p < 0.05) and 6 months (IRR = 0.56; 95% CI = 0.38 to 0.83; p < 0.01). Models examining interaction effects were significant for the CBI on moderate dating victimization at 3 months (IRR = 0.81; 95% CI = 0.67 to 0.98; p < 0.05) and 6 months (IRR = 0.81; 95% CI = 0.66 to 0.99; p < 0.05). Significant interaction effects were found for the T+CBI on moderate dating violence victimization at 6 months (IRR = 0.81; 95% CI = 0.69 to 0.96; p < 0.01) and 12 months (IRR = 0.76; 95% CI = 0.63 to 0.90; p < 0.001) and severe dating violence victimization at 3 months (IRR = 0.76; 95% CI = 0.59 to 0.96; p < 0.05). CONCLUSIONS: ED-based BIs tailored to address multiple risk behaviors (i.e., peer violence, alcohol use, and dating violence) show promise for reducing moderate and severe dating victimization for up to 1 year following an ED visit.

Emergency department-based brief intervention to reduce risky driving and hazardous/harmful drinking in young adults: a randomized controlled trial.

BACKGROUND: Risky driving and hazardous drinking are associated with significant human and economic costs. Brief interventions for more than one risky behavior have the potential to reduce health-compromising behaviors in populations with multiple risk-taking behaviors such as young adults. Emergency department (ED) visits provide a window of opportunity for interventions meant to reduce both risky driving and hazardous drinking. METHODS: We determined the efficacy of a Screening, Brief Intervention, and Referral to Treatment (SBIRT) protocol addressing risky driving and hazardous drinking. We used a randomized controlled trial design with follow-ups through 12 months. ED patients aged 18 to 44 who screened positive for both behaviors (n = 476) were randomized to brief intervention (BIG), contact control (CCG), or no-contact control (NCG) groups. The BIG (n = 150) received a 20-minute assessment and two 20-minute interventions. The CCG (n = 162) received a 20-minute assessment at baseline and no intervention. The NCG (n = 164) were asked for contact information at baseline and had no assessment or intervention. Outcomes at 3, 6, 9, and 12 months were self-reported driving behaviors and alcohol consumption. RESULTS: Outcomes were significantly lower in BIG compared with CCG through 6 or 9 months, but not at 12 months: Safety belt use at 3 months (adjusted odds ratio [AOR], 0.22; 95% confidence interval [CI], 0.08 to 0.65); 6 months (AOR, 0.13; 95% CI, 0.04 to 0.42); and 9 months (AOR, 0.18; 95% CI, 0.06 to 0.56); binge drinking at 3 months (adjusted rate ratio [ARR] 0.84; 95% CI, 0.74 to 0.97) and 6 months (ARR, 0.81; 95% CI, 0.67 to 0.97); and ≥5 standard drinks/d at 3 months (AOR, 0.43; 95% CI, 0.20 to 0.91) and 6 months (AOR, 0.41; 95% CI, 0.17 to 0.98). No substantial differences were observed between BIG and NCG at 12 months. CONCLUSIONS: Our findings indicate that SBIRT reduced risky driving and hazardous drinking in young adults, but its effects did not persist after 9 months. Future research should explore methods for extending the intervention effect.

Graduated driver licensing for new drivers: effects of three states' policies on crash rates among teenagers.

BACKGROUND: Evidence is mixed on the effects of graduated driver licensing (GDL) on motor vehicle crashes involving drivers aged 18 years. PURPOSE: This study examined the effects of GDL on crashes involving drivers aged 18 years in three states: Maryland, where GDL applies to novice drivers of all ages, and Florida and Michigan, where GDL applies only to new drivers aged <18 years. In addition, this study sought to confirm positive effects of GDL among drivers aged 16 and 17 years. METHODS: Monthly rates for three levels of crash severity (fatal/disabling injury, nondisabling injury, and possible injury/property damage only [PDO]) for drivers aged 16, 17, and 18 years were calculated using crash records and census data. Data for Maryland spanned 1998 to 2009, for Florida 1990 to 2009, and Michigan 1992 to 2009. GDL's effects on teen driver crashes by age were estimated using time-series analyses, conducted in 2012. RESULTS: Crash rates for drivers aged 16 and 17 years declined in all three states following implementation or revision of GDL. For drivers aged 18 years, revision of an existing GDL law in Maryland was followed by a 6.9% decrease in possible-injury/PDO crashes; in Michigan, GDL implementation was followed by a 3.6% increase in possible-injury/PDO crashes; and in Florida, GDL had no effect. CONCLUSIONS: GDL led to expected declines in crash rates for drivers aged 16 and 17 years. However, the findings suggest that when GDL applies only to novice drivers aged <18 years, rather than to all novice drivers, crash rates among drivers aged 18 years may increase. In order to potentially extend the safety benefits of GDL, the age at which GDL for new drivers should be applied requires further attention.

Inexperience and risky decisions of young adolescents, as pedestrians and cyclists, in interactions with lorries, and the effects of competency versus awareness education.

BACKGROUND: Road injuries are a prime cause of death in early adolescence. Often road safety education (RSE) is used to target risky road behaviour in this age group. These RSE programmes are frequently based on the assumption that deliberate risk taking rather than lack of competency underlies risk behaviour. This study tested the competency of 10-13 year olds, by examining their decisions - as pedestrians and cyclists - in dealing with blind spot areas around lorries. Also, the effects of an awareness programme and a competency programme on these decisions were evaluated. METHOD: Table-top models were used, representing seven scenarios that differed in complexity: one basic scenario to test the identification of blind spot areas, and 6 traffic scenarios to test behaviour in traffic situations of low or high task complexity. Using a quasi-experimental design (pre-test and post-test reference group design without randomization), the programme effects were assessed by requiring participants (n=62) to show, for each table-top traffic scenario, how they would act if they were in that traffic situation. RESULTS: On the basic scenario, at pre-test 42% of the youngsters identified all blind spots correctly, but only 27% showed safe behaviour in simple scenarios and 5% in complex scenarios. The competency programme yielded improved performance on the basic scenario but not on the traffic scenarios, whereas the awareness programme did not result in any improvements. The correlation between improvements on the basic scenarios and the traffic scenarios was not significant. CONCLUSIONS: Young adolescents have not yet mastered the necessary skills for safe performance in simple and complex traffic situations, thus underlining the need for effective prevention programmes. RSE may improve the understanding of blind spot areas but this does not 'automatically' transfer to performance in traffic situations. Implications for the design of RSE are discussed.

Changing mobility patterns and road mortality among pre-license teens in a late licensing country: an epidemiological study.

BACKGROUND: Whereas the safety of teens in early licensing countries has been extensively studied, little is known about the safety of pre-license teens in late licensing countries, where these teens also may be at risk. This risk exists because of the combination of a) increasing use of travel modes with a high injury risk, such as bicycles and mopeds, b) inexperience, and c) teens' developmental stage, known to be associated with risk taking and novelty seeking, especially among males. To explore the magnitude and nature of pre-license road risk, this study analysed epidemiological data from the Netherlands, and hypothesized that in this late licensing country, 'independent travel' and the use of riskier modes of transport increase among pre-license teens 10 to 17 years of age, resulting in higher fatality rates, with 'experience' and 'gender' as risk modifying factors. METHOD: National travel and fatality data of pre-license adolescents in the Netherlands were analysed by traffic role (cyclist, pedestrian, car passenger and moped rider), and compared to a younger age group (0-9 years) and an older age group (18+ years). RESULTS: The study of travel data showed that teens migrate from being car occupants to being users of riskier modes of transport, specifically bicycles and mopeds. This migration resulted in a strong rise in road fatalities, illustrating the importance of mobility patterns for understanding changes in road fatalities in this age group. The data further suggested a protective role of early cycle experience for young adolescent cyclists, particularly for young males. But further study into the underlying mechanism is needed to confirm this relationship. Moped risk was extremely high, especially among young males, and even higher than that of young male car drivers. CONCLUSIONS: The study confirmed the importance of changes in mobility patterns for understanding the rising road mortality when youngsters enter into their teens. The focus on fatalities has led to an underestimation of the magnitude of the problem because of the physical resilience of young adolescents that leads to high survival rates but probably also to long term disabilities. In addition, to explore the generalizability of these results, international comparisons among and between early and late licensing countries are necessary, especially in relation to moped riding as an alternative for car driving.