The New Zealand graduated driver licensing system: teenagers' attitudes towards and experiences with this car driver licensing system

Parental influence on adolescent compliance with graduated driver licensing conditions and crashes as a restricted licensed driver: New Zealand drivers study

AIM

To examine the influence of parental knowledge of, and support for graduated driver licensing (GDL) conditions, parental management of adolescent driving and parental driving behaviour on adolescent compliance with GDL conditions and crashes as a restricted licence driver.

METHOD

This research was part of the New Zealand Drivers Study (NZDS), a prospective cohort study of 3992 newly licensed car drivers. NZDS participants were recruited at the learner licence stage, with follow-up aligned with the GDL stages. At the restricted licence stage 1200 parents of NZDS adolescents, aged 15-17 years at learner licensure, were recruited and completed interviews. 895 of these adolescents progressed to their full licence and completed the full licence interview. These 895 parent-adolescent pairs were the study population in this research. Topics examined included parental knowledge of, and support for GDL conditions, management of adolescent driving (driving rules, adolescent vehicle ownership, delaying licensure), and their own driving behaviours. Outcomes examined were adolescent compliance with GDL restricted licence conditions (night-time and passenger), and crashes as a driver during the restricted licence stage.

RESULTS

After controlling for other variables, factors independently associated with adolescent low compliance with GDL conditions were: low parental knowledge of conditions, parents' implementing few driving rules, adolescent vehicle ownership, and parent crash involvement. Factors independently associated with adolescents being a crash involved driver were: parents' actively delaying licensure, adolescent vehicle ownership, and parent crash involvement.

CONCLUSION

There is increasing recognition of the importance of parental involvement in adolescent driving. The results show that parents are influential in determining adolescent compliance with GDL and risk of crash. Parents can have considerable positive influence on their adolescent's driving through ensuring compliance with the components of GDL, limiting vehicle ownership and by modelling safe driving behaviours.

Analysis of factors associated with injury severity in crashes involving young New Zealand drivers

Young people are a risk to themselves and other road users, as motor vehicle crashes are the leading cause of their death. A thorough understanding of the most important factors associated with injury severity in crashes involving young drivers is important for designing well-targeted restrictive measures within youth-oriented road safety programs. The current study estimates discrete choice models of injury severity of crashes involving young drivers conditional on these crashes having occurred. The analysis examined a comprehensive set of single-vehicle and two-vehicle crashes involving at least one 15-24 year-old driver in New Zealand between 2002 and 2011 that resulted in minor, serious or fatal injuries. A mixed logit model accounting for heterogeneity and heteroscedasticity in the propensity to injury severity outcomes and for correlation between serious and fatal injuries proved a better fit than a binary and a generalized ordered logit. Results show that the young drivers' behavior, the presence of passengers and the involvement of vulnerable road users were the most relevant factors associated with higher injury severity in both single-vehicle and two-vehicle crashes. Seatbelt non-use, inexperience and alcohol use were the deadliest behavioral factors in single-vehicle crashes, while fatigue, reckless driving and seatbelt non-use were the deadliest factors in two-vehicle crashes. The presence of passengers in the young drivers' vehicle, and in particular a combination of males and females, dramatically increased the probability of serious and fatal injuries. The involvement of vulnerable road users, in particular on rural highways and open roads, considerably amplified the probability of higher crash injury severity.

Adolescence extended: implications of new brain research on medicine and policy

Last December, the Excellence in Paediatrics conference presented a panel discussion of how new biologic findings from brain imaging cast new light on adolescent development. This study will review this presentation, focusing on the interplay between adolescent development and new brain research findings.

CONCLUSION

Paediatricians can consider these new insights in both interacting individually with patients and advocating for policies within their communities.

Adolescent, and their parents, attitudes towards graduated driver licensing and subsequent risky driving and crashes in young adulthood

PROBLEM

Although Graduated Driver Licensing Systems (GDLS) have helped reduce young driver crash rates, they remain significantly over-represented in crash statistics. To be effective GDLS rely heavily on support for the legislation by those directly involved; parents to enforce the restrictions and adolescents to comply. There is some evidence that practices regarding GDLS restrictions influence adolescent driving outcomes in the early stage of licensure. However there has been no examination undertaken on the influence of parent and adolescent attitudes toward GDLS on adolescents' driving behavior and crash experiences as they move into their young adult years. The aim of this research was to examine these relationships.

METHOD

This investigation was based on a longitudinal study of a birth cohort, and uses data collected when the cohort members were aged 15, 18, and 21years. At age 15 both adolescent and their parent attitudes toward GDLS were measured. At age 18 adolescent GDLS attitudes were measured again. The association between these measures and self-reported risky driving behavior and crash involvement at age 21 were examined.

RESULTS

Negative attitudes toward the learner supervisor restriction for males, and negative attitudes toward a GDLS for females were strongly associated with risky driving and crash involvement as young adults.

IMPACT ON INDUSTRY

Targeting interventions to improve adolescents and parents understanding of the reasons for graduated licensing and the specific restrictions may improve attitudes and views and thereby contribute to a reduction in risky driving behaviors and crash risk among young adults.

Attitudes of teenagers and their parents to Pennsylvania's graduated driver licensing system

OBJECTIVES

To determine the attitudes of teens and parents in Pennsylvania (PA) towards the enhanced graduated driver licensing (GDL) system implemented in 2000, and to assess their understanding of teen crash risk.

METHODS

Cross-sectional survey of teen drivers and their parents. Eligible teens were 16 or 17 years old when they obtained their first learner's permits in 2000. A simple random sample of 2500 was obtained from 48,372 meeting inclusion criteria. Questions were based on previous surveys and pre-tested in focus groups.

ANALYSIS

Chi-square, McNemar, or t-tests, as appropriate.

RESULTS

A total of 1561 surveys (811 parents and 750 teens) were included in the analysis. There were no differences between the sample and teen respondents. Their junior license had been achieved by 735 (98%) teens and had been driving unsupervised for a mean of 14.1 months (SD 4.89). Greater than ninety percent (90%) of parents approved of the overall system, the six-month learner phase, and the requirement for parental certification of 50 hours of supervised driving. The teens' reactions were less positive than the parents' (p < 0.001), but only 16% reported a negative overall reaction. 31.4% of the teens reported not completing the required 50 hours of supervised driving. 70.6% of parents felt the nighttime driving restriction was "just right" at 11 pm but 54.0% of teens preferred that it be returned to 12 mn (p < 0.001). When asked about the crash rate for teen drivers, 72.8% of teens and 74.0% of parents chose rates 2 to 100 times less than the reported crash rate (p = 0.8).

CONCLUSIONS

In PA, the primary stakeholders, teen drivers and their parents, were poorly informed about teen crash risk. Parents were very positive and teens are generally neutral or weakly positive about the new restrictions imposed by the enhanced graduated driver licensing system. Better understanding of the crash rate for teen drivers might increase approval of system restrictions, enhance compliance, and further strengthen the system.

Child passenger injury risk in motor vehicle crashes: a comparison of nighttime and daytime driving by teenage and adult drivers

INTRODUCTION

To examine the association between child passenger injury risk, restraint use, and crash time (day vs. night) for children in crashes of vehicles driven by teenage versus adult drivers.

METHODS

Cross-sectional study involving telephone interviews with insured drivers in a probability sample of 6,184 crashes involving 10,028 children.

RESULTS

Child passengers in teen nighttime crashes had an increased injury risk and an increased risk of restraint nonuse compared with those in teen daytime crashes. This increased injury risk can be explained by differences in the age of child passengers, collision type, and child passenger's restraint status associated with time of day.

CONCLUSIONS

In order to limit the risk of injury to child passengers driven by teens, Graduated Driver Licensing (GDL) laws should include provisions restricting nighttime driving, as well as mandates for age-appropriate restraint for child passengers. Consideration should also be given for education in child passenger safety for novice teen drivers as part of the licensing process.

IMPACT ON INDUSTRY

Results of this study can be used to support advocacy efforts by the automotive industry and others to promote nighttime driving restrictions on novice drivers. In addition, given that both driver groups were more likely to be involved in a single-vehicle collision during the night, technologies such as electronic stability control may offer opportunities for protection. Further reseach on specific circumstances of teen nighttime crashes is needed to inform industry efforts to improve visibility or vehicle operation under poor lighting conditions.

Encouraging compliance with graduated driver licensing restrictions

PROBLEM

Although graduated driver licensing (GDL) programs have reduced the high crash rates for 16-and 17-year-old drivers, research suggests that some teenagers fail to comply with restrictions on nighttime driving and carrying passengers.

METHOD

A program to encourage compliance with GDL restrictions and seat belt requirements was implemented in Guilford County, North Carolina. The program combined increased enforcement with a multi-faceted publicity campaign drawing attention to the enforcement activity. A comparison community was studied to assess whether changes over time could be reasonably attributed to the program.

RESULTS

Several measures indicate that greater enforcement did occur in the intervention community and that teenagers perceived the increase. However, self-reported data and direct observations of young drivers in the intervention and comparison communities showed the program resulted in only modest changes in compliance with GDL restrictions.

DISCUSSION

The program put in place the mechanisms known to produce changes in driver behavior, but these may have been insufficient to alter the behavior of the minority of teenagers (and parents) who were not already complying with restrictions. However, the modest changes in young driver behavior plus the clear changes in both actual and perceived enforcement suggest that high visibility enforcement programs merit further use and evaluation in other communities, particularly those where compliance with GDL provisions is lower than in Guilford County.

Graduated driver licensing in Utah: Is it effective?

STUDY OBJECTIVE

We seek to examine the effectiveness of the graduated driver licensing system in Utah by determining whether crash rates of 16-year-old drivers decreased after graduated driver licensing implementation.

METHODS

We studied 16-year-old-driver crashes using statewide motor vehicle crash data probabilistically linked to emergency department (ED), hospital inpatient, and driver licensure data for 1996 to 2001. Outcomes examined included overall crash rates, nighttime crashes, crash severity indicators (eg, noninjury crash, injury crash, ED crash, inpatient crash, fatal crash), seat belt usage, licensure status, and citations. Rate ratios (RR), chi 2 tests, and interventional time series analyses were used to assess changes before and after graduated driver licensing implementation.

RESULTS

There were 27,304 16-year-old-driver crashes during the study period. The overall crash rate per 1,000 licensed 16-year-old drivers decreased by 5% (RR 0.95; 95% confidence interval [CI] 0.92 to 0.97), and a time-series analysis showed a reduction of 0.8 (SD 0.39) crashes per month per 1,000 licensed drivers after graduated driver licensing implementation (1996 to 1999 versus 1999 to 2001). The nighttime crash rate did not change (RR 0.91; 95% CI 0.78 to 1.04), and there was no association between crash severity and graduated driver licensing implementation ( P =.096). Reported seat belt usage increased by 6.3%, and few graduated driver licensing citations were issued by law enforcement.

CONCLUSION

The results suggest that graduated driver licensing may have contributed to a reduction in young driver crashes, but the effects were minimal compared with those shown in many other graduated driver licensing evaluations.

Probationary and non-probationary drivers' nighttime crashes in Western Australia, 1996-2000

INTRODUCTION

This study was designed to explore the temporal aspects of crashes for probationary and non-probationary drivers.

METHODS

Data from the West Australian Road Injury Database from 1996-2000 were used to calculate age-sex-specific crash rates per 100,000 person-days and to plot proportions of fatal and hospital crashes by time for probationary and non-probationary drivers. The population attributable risk was used to estimate the potential number of lives saved by nighttime driving restriction in the probationary period.

RESULTS

Probationary drivers were seven times more likely to crash than non-probationary drivers. While the highest number of crashes was in the daytime, probationary drivers had a higher proportion of fatal or hospitalization crashes at night than non-probationary drivers.

CONCLUSION

Restrictions on driving at night could form part of graduated driver training. Even if some probationary drivers disobeyed the restriction, a substantial reduction in car occupant fatalities and hospitalizations could result.

Identifying predictors of persistent non-alcohol or drug-related risky driving behaviours among a cohort of young adults

This study sought to identify adolescent risk factors that predicted persistent risky driving behaviours among young adults. It was part of a longitudinal study of a birth cohort (474 males and 459 females). The potential predictors were self-reported data obtained at ages 15, 18, 21 years (academic qualifications, personality, mental health, anti-social behaviour and driving behaviour). The risky driving behaviour outcomes were obtained at ages 21 and 26 years and included driving fast for thrills, taking deliberate risks for fun, excessive speed, dangerous overtaking, and close following (tailgating). Persistent risky drivers were defined as those who often, or fairly often engaged in a behaviour at both ages. A minority of males and very few females were classified as persistent risky drivers. Among the males, the factors that predicted at least one, or more of the outcomes were the personality trait of low constraint (i.e. low scores for control, harm avoidance, and traditionalism), aggressive behaviour, and cannabis dependence. These are characteristics to be borne in mind when developing programmes for young drivers that aim to deter the development of persistent risky driving behaviour.

Graduated driver licensing restrictions: awareness, compliance, and enforcement in North Carolina

PROBLEM

This study examined the extent to which critical restrictions in North Carolina's graduated driver licensing (GDL) system are known, adhered to, and enforced.

METHOD

Teenagers and their parents were recruited as they applied for either an intermediate or full license at 1 of 23 licensing offices. Telephone interviews were conducted with 900 teenagers and their parents.

RESULTS

Awareness of North Carolina's night and passenger restrictions was very high among both parents and teenagers. Ten percent of teenagers reported violating the night restriction without their parents' knowledge, and 15% had done so with their parents' approval. Only 4% of parents reported allowing their teenagers to drive with more than one teenage passenger, but 19% of teenagers reported that they were allowed to do this. Violations of the passenger restriction without parental knowledge were more common than violations of the night restriction (22% vs. 10%, respectively). Among teenagers who violated restrictions without their parents' knowledge, most reported doing so only once or a few times. Teenagers expressed little concern about detection, although a majority reported driving more carefully to avoid police notice. Neither parents nor teenagers knew much about police enforcement of GDL restrictions. To obtain a sense of the views of law enforcement officers, informal interviews were conducted with 20 officers from five diverse communities and the state highway patrol. These officers were highly supportive of GDL but unfamiliar with many of the specific provisions. Moreover, enforcement of GDL restrictions did not appear to be a high priority.

IMPACT ON INDUSTRY

There is a need to increase the belief among teens (and parents) that police are enforcing GDL restrictions in their community; law enforcement participation in well-publicized traffic safety enforcement efforts would likely produce this result.

Graduated driver licensing for reducing motor vehicle crashes among young drivers

BACKGROUND

Graduated driver licensing (GDL) has been proposed as a means of reducing crash rates among novice drivers by gradually introducing them to higher risk driving situations.

OBJECTIVES

To examine the effectiveness of GDL systems in reducing crash rates of young drivers.

SEARCH STRATEGY

Studies were identified through searches of MEDLINE, EMBASE, CINAHL, Healthstar, Web of Science, NTIS Bibliographic Database, TRIS Online, SIGLE, the World Wide Web, relevant conference proceedings, consultation with experts and authors, and reference lists. The search was not restricted by language or publication status.

SELECTION CRITERIA

Studies were included if: 1) they compared outcomes pre- and post-implementation of a GDL program within the same jurisdiction, 2) comparisons were made between jurisdictions with and without GDL, or 3) both. Studies had to report at least one objective, quantified outcome. Two reviewers independently screened searches and assessed the full text of potentially relevant studies for inclusion using a standard form.

DATA COLLECTION AND ANALYSIS

Data were extracted by one reviewer and checked by a second. Additional data were requested from authors. Results were not pooled due to substantial heterogeneity between studies. Percentage change was calculated for each year after the intervention, using one year prior to the intervention as the baseline rate. Results were adjusted by internal controls. Analyses were stratified by different denominators (population, licensed drivers). Results were calculated for the different crash types (overall, injury, fatal, night-time, alcohol, and those resulting in hospitalization). Results were presented for 16 year-olds alone and all teenage drivers combined.

MAIN RESULTS

We included 13 studies evaluating 12 GDL programs that were implemented between 1979 and 1998 in the US (n=7), Canada (3), New Zealand (1), and Australia (1). Programs varied in their restrictions during the intermediate stage: e.g. night curfews (8); limitations of extra passengers (2); roadway restrictions (1). Based on the Insurance Institute for Highway Safety classification scheme, no programs were good, six were acceptable, five were marginal, and one was poor. Reductions in crash rates were seen in all jurisdictions and for all crash types. Among 16 year-old drivers, the median decrease in per population overall crash rates during the first year was 31% (range 26-41%). Per population injury crash rates were similar (median 28%, range 4-43%). Results for all teenage drivers, rates per licensed driver, and rates adjusting for internal controls were generally reduced when comparing within jurisdictions.

REVIEWERS' CONCLUSIONS

The existing evidence shows that GDL is effective in reducing the crash rates of young drivers, although the magnitude of the effect is unclear. The conclusions are supported by consistent direction of the findings, and the temporal relationship and plausibility of the association. The reviewers have made recommendations for primary research on GDL (e.g. study methods, standardized reporting of outcomes and results, long-term follow-up). The project has also shown what is needed to carry out systematic reviews of observational studies (e.g. quality assessment instruments).

Identifying factors that predict persistent driving after drinking, unsafe driving after drinking, and driving after using cannabis among young adults

The main aim of this study was to identify adolescent/young adulthood factors that predicted persistent driving after drinking, persistent unsafe driving after drinking, and persistent cannabis use and driving among young adults. It was a longitudinal study of a birth cohort (n=933, 474 males and 459 females) and was based on data collected at ages 15, 18, 21 and 26 years. At each of these ages members of the cohort attended the research unit for a personal interview by a trained interviewer, using a standardised questionnaire. For this study, the data for the outcome measures (persistent driving after drinking, persistent unsafe driving after drinking, and persistent driving after using cannabis) were obtained at ages 21 and 26 years. The main explanatory measures were collected at ages 15, 18, 21 years and included demographic factors (academic qualifications, employment, parenting); personality measures; mental health measures (substance use, cannabis dependence, alcohol dependence, depression); anti-social behaviour (juvenile arrest, aggressive behaviour, court convictions); early driving behaviour and experiences (car and motorcycle licences, traffic crashes). The analyses were conducted by gender. The results showed that females who persisted in driving after drinking (13%, n=61) were more likely than the others to have a motorcycle licence at 18. The males who persisted in driving after drinking (28%, n=135) were more likely than the other males to have some school academic qualifications and to be employed at age 26. Compared to the other males, those who persisted in unsafe driving after drinking (4%, n=17) were more likely to be aggressive at 18 and alcohol dependent at 21. Only six (1%) females persisted in unsafe driving after drinking so regression analyses were not conducted for this group. For persistent driving after using cannabis, the univariate analyses showed that females who persisted with this behaviour tended to have high substance use at 18, cannabis dependence at 21, police contact as a juvenile, and to be a parent at 21. For this group, because of the small numbers (3%, n=13) multivariate analyses were not appropriate. For the males who persisted in driving after using cannabis (14%, n=68) a wide range of variables were significant at the univariate stage. The multivariate analysis showed that the most important factors were dependence on cannabis at 21, at least one traffic conviction before 21, a non traffic conviction before 18, and low constraint at 18.

CONCLUSION

These results show different characteristics were associated with persistence in each of these outcome behaviours. This indicates that different approaches would be required if intervention programmes were to be developed to target these behaviours.

Enhancing the effectiveness of graduated driver licensing legislation

PROBLEM

Many states have enacted graduated driver licensing (GDL) systems in an effort to reduce the very high crash rates of young beginning drivers. This article addresses how to achieve the maximum benefit from GDL by ensuring compliance with protective restrictions.

ENHANCING GDL THROUGH SYSTEM STRUCTURE

The major crash reductions due to GDL systems result from the protective restrictions during the initial two levels, which isolate novice drivers from the highest risk driving situations. Accordingly, GDL systems should include protective restrictions that adequately control the greatest dangers facing young drivers: multiple teen passengers and night driving before midnight.

ENCOURAGING COMPLIANCE THROUGH SYSTEM STRUCTURE

Including protective restrictions that are supported by parents and teens will encourage compliance. Furthermore, linking a teen's advancement through GDL to demonstrated responsible driving will likely encourage compliance more than threatening punishment for violations.

ENCOURAGING COMPLIANCE THROUGH ENFORCEMENT

Parents are in a prime position to enforce most GDL restrictions, but there is some evidence they do not enforce those restrictions that they consider too extreme. Little is currently known about the involvement of law enforcement in GDL systems, but there is potential for high visibility law enforcement activities to encourage compliance with restrictions.

IMPACT ON RESEARCH, PRACTICE, AND POLICY

There is a need for better designed GDL systems in many states; more research is needed to examine compliance with restrictions and to evaluate enforcement efforts by parents and law enforcement.

Graduated driver licensing: the New Zealand experience

In New Zealand, on 1 August 1987, a three-stage graduated driver licensing (GDL) system that applied to all new drivers aged 15-24 years was introduced. The essential elements of GDL were a 6-month learner license (supervised driving) and an 18-month restricted license stage (with restrictions on night driving and carrying passengers). A blood alcohol limit of 0.03 mg% applied at both stages. EVALUATION STUDIES: Early studies indicated that young people were reasonably accepting of the restrictions, with the passenger restriction being the least acceptable. Problems of compliance with the restricted license driving restrictions were reported. Evaluations of the impact of the graduated driver licensing (GDL) on serious traffic-related injury showed that up until 1991-1992, an 8% reduction could be attributed to GDL. At this time, it was considered that reduced exposure was the main reason for this reduction. However, the number of fatalities and hospital admissions among young people continued to decline, as did the population rate and the rate per number of licensed drivers among the young driver age group. A further evaluation study showed that drivers with a restricted license had a smaller proportion of crashes at night, and with passengers, compared with drivers licensed before GDL. IMPACT OF GDL: These results suggested that GDL restrictions had contributed to the reduction in crashes among young people and that it was not simply a case of reduced exposure to risk. An update of the most recent crash statistics indicated that, compared with older age groups, the fatal and serious injury crash rate among young people has remained substantially below the pre-GDL level. This suggests that the impact of GDL has not diminished over time.

Driving beliefs and behaviors of novice teen drivers and their parents: implications for teen driver crash risk

This project was a cross sectional survey of 739 matched family pairs of recently licensed teens and their parents. It was designed to assess the relationship of driving behaviors between parents and teens and to investigate predictors of teen crashes. One third of teens reported being involved in a crash during an average of 14 months of driving while 19.9% reported received a moving violation. Teens reported engaging in most risky driving behaviors more frequently than their parents. Teen and parental driving behaviors were associated, but the level of association was low, suggesting that other factors may outweigh parental influence. In multivariate analysis, only the teen's belief about their crash risk and whether the teen had received a moving violation were associated with reporting a crash.

Responses of teenagers and their parents to California's graduated licensing system

In 1998, California adopted a strong graduated licensing system that lengthened the learner's permit stage from 1 month to a mandatory 6 months and introduced passenger and nighttime restrictions for initial license holders. The passenger restriction (no passengers younger than 20 for the first 6 months) is stronger than such restrictions in any other state; the nighttime ban is relatively weak, not beginning until midnight. Surveys were undertaken to learn what teenagers and their parents thought about the new requirements and how they responded to them. Two groups of beginning California license holders were surveyed three times during the first year of licensure; their parents were interviewed twice. One group (n = 543) was subject to the graduated licensing requirements, the other (n = 814) was not. Parents strongly endorsed the new system. The vast majority approved of the new permit requirements and the nighttime and passenger restrictions. Among parents whose children were subject to the new requirements, 79% were strongly in favor of the new system and only 4% were neutral or opposed. Teenagers were less favorable toward the new requirements. Most approved of the new learner's permit rules, and the majority of teenagers favored the night restriction, but only about one-third endorsed the passenger restriction. Compliance with the new rules was not close to universal, but the new licensing system resulted in young people holding their learner's permits longer, accumulating more practice driving prior to licensure and decreased the amount of reported driving after midnight and transportation of teenagers when initially licensed. Most teenagers subject to the new rules said they were able to do the activities they wanted despite the changes; almost three-quarters said they were not affected much by either the nighttime or passenger restriction. Overall the results indicate that the new licensing system is accepted favorably by teenagers and their parents and has substantially increased the types of behaviors that collectively should lead to crash and injury reductions.

Impact of graduated driver licensing restrictions on crashes involving young drivers in New Zealand

OBJECTIVE

To determine the impact on young driver crashes of the three main driving restrictions in the New Zealand graduated driver licensing (GDL) system: night-time curfew, no carrying of young passengers, and a blood alcohol limit of 30 mg/100 ml.

METHOD

The database for this study was created by linking police crash reports to hospital inpatient records (1980-95). Multivariate logistic regression was used to compare car crashes involving a young driver licensed before GDL (n=2,252) with those who held a restricted graduated licence (n=980) and with those who held a full graduated licence (n=1,273), for each of the main driving restrictions.

RESULTS

Compared with the pre-GDL group, the restricted licence drivers had fewer crashes at night (p=0.003), fewer involving passengers of all ages (p=0.018), and fewer where alcohol was suspected (p=0.034), but not fewer involving young casualties (p=0.980). Compared with the pre-GDL drivers, those with the full graduated licence had fewer night crashes (p=0.042) but did not differ significantly for any of the other factors examined.

CONCLUSION

These results suggest that some of the GDL restrictions, especially the night-time curfew, have contributed to a reduction in serious crashes involving young drivers.

Potential benefits of restrictions on the transport of teenage passengers by 16 and 17 year old drivers

OBJECTIVES

The presence of passengers is associated with fatal motor vehicle crashes of teenage drivers. A restriction against newly licensed teenage drivers carrying passengers has been included in some, but not all, graduated licensing systems. The purpose of this study was to predict the net effects on all types of road users, including vehicle occupants and non-occupants, of possible prohibitions against 16-17 year old drivers carrying passengers.

METHODS

Two national datasets, a census of fatal crashes and a sample of trips in the United States, were used to compute 1995 road user death rates. Potential effects of restrictions on drivers ages 16-17 carrying passengers younger than 20 were estimated, based on road user death rates and potential choices made by passengers who would have traveled with 16-17 year old drivers if there were no restrictions.

RESULTS

There were 1,181 road user deaths in 1995 involving drivers ages 16-17 whose passengers were all younger than age 20. The predicted number of lives in the United States that would be saved annually ranges from 83 to 493 (corresponding to reductions of 7-42% in road user deaths) for drivers ages 16 and 17 combined. Similar percentages of reductions (8-44%) were predicted solely for 16 year old drivers. Assuming passenger restrictions would apply to all 16 year old drivers and at least one third of 17 year old drivers, an estimated 60-344 fewer deaths per year may occur if restrictions are mandated.

CONCLUSIONS

Restrictions on carrying passengers younger than 20 should be considered for inclusion in graduated licensing systems. Even if fewer than half the drivers obey the restrictions, a substantial reduction in road user deaths would be expected. Further evaluation based on real world experience is needed to confirm their efficacy.

A population-based study of crashes involving 16- and 17-year-old drivers: the potential benefit of graduated driver licensing restrictions

OBJECTIVE

To evaluate the potential effectiveness of graduated driver licensing programs using population-based linked data for motor vehicle crashes (MVCs) that involved teenaged drivers (TDs).

METHODS

Utah crash, inpatient hospital discharge, and emergency department databases were analyzed and probabilistically linked. We computed hospital charges and compared violations, contributing factors, seatbelt use, and passengers for TDs (16-17 years old) relative to adult drivers (18-59 years old).

RESULTS

TDs comprised 5.8% of the study population, but were involved in 19.0% of MVCs. TD crashes resulted in $11 million in inpatient hospital charges and 158 fatalities. TD crashes were 1.70 times (95% confidence interval [CI]: 1.34, 2.04) less likely to result in fatal injury to drivers than were crashes that involved adult drivers, but TDs were 2.20 times (95% CI: 1.96, 2.47) more likely to receive citations. The following were findings of the study: 1) 11% of all TD crashes but 19% of fatal TD crashes occurred between 2200 and 0600 hours; 2) TDs used seatbelts less often than did adult drivers (79.1% vs 84.4%) and less often with passengers present (81.9% vs 75.0%; 3) TDs were 1.72 times (95% CI: 1.38, 2.14) more likely to be involved in crashes that resulted in seriously or fatally injured occupants when driving with passengers than when driving alone.

CONCLUSIONS

TDs are overrepresented in MVCs. TD crashes have a higher fatality rate at night, and TDs wear seatbelts less often than do adult drivers. Passengers affect TD crash characteristics. Graduated driver licensing programs that target state-specific characteristics of TDs may decrease morbidity and mortality.

A longitudinal study of lifestyle factors as predictors of injuries and crashes among young adults

This study was part of the Dunedin Multidisciplinary Health and Development Study. This is a longitudinal study of the health, development and behaviour of a cohort of 1037 young people born in Dunedin, New Zealand between 1 April 1972 and 31 March 1973. Explanatory measures covering background, behavioural and personality factors were obtained at ages 15 and 18 and were used as potential predictors of outcomes reported at age 21. Four outcomes were considered: any crash, injury crash, non-injury crash, and serious injury (not motor vehicle related). Overall, very few lifestyle factors were important predictors of any of these outcomes. Factors that were shown to predict injury crashes differed from those that predicted non-injury crashes. Also, those that predicted a traffic crash differed from those that predicted a serious non-traffic injury. These results suggest that focusing injury prevention efforts on changing the lifestyles of young adults is unlikely to reduce overall crash risk, and would have little impact on the risk of serious injury.

Inattentive and hyperactive behaviors and driving offenses in adolescence

OBJECTIVE

The associations between symptoms of attention-deficit hyperactivity disorder (ADHD), conduct disorder, anxiety, or depression and no disorder in relation to driving offenses were examined in 916 adolescents.

METHOD

Self-report and parent report were used to assess a birth cohort of New Zealand adolescents' mental health status at age 15 years. Adolescents who scored 1.5 SD above the mean on the DSM-III total ADHD symptom scale were identified as reporting significant ADHD symptomatology. Self-report data and official traffic conviction records were used to identify adolescents who had committed driving offenses between ages 15 and 18 years.

RESULTS

ADHD symptomatology and conduct disorder were strongly associated with driving offenses. ADHD symptomatology in females was significantly associated with driving offenses and more traffic crashes compared with other disorder or no disorder.

CONCLUSIONS

Adolescents with a history of ADHD and conduct problems are significantly more likely than their peers to commit traffic offenses. Research in ADHD and risky driving should include female adolescents, as those with attentional difficulties are at a high risk for being involved in traffic crashes than females who do not experience attentional difficulties.

Earning a driver's license

Teenage drivers in the United States have greatly elevated crash rates, primarily a result of qualities associated with immaturity and lack of driving experience. State licensing systems vary substantially, but most have allowed quick and easy access to driving with full privileges at a young age, contributing to the crash problem. Formal driver education has not been an effective crash prevention measure. Following the introduction of graduated licensing in New Zealand, Australia, and Canada, this system has been considered in many states and has been implemented in some. Graduated systems phase in full privilege driving, requiring initial experience to be gained under conditions of lower risk. The author describes the first five multistage graduated systems enacted in the United States in 1996 and 1997. Factors that will influence the acceptability and effectiveness of these new licensing systems are discussed.

An evaluation of the New Zealand graduated driver licensing system

Young drivers have a disproportionately high risk of experiencing a road traffic crash. On 1 August 1987 a Graduated Driver's Licensing System (GDLS) was introduced in New Zealand. This system was designed to give young drivers (i.e. 15-24 years inclusive) experience in driving while being excluded from high risk driving situations. We sought to determine the impact of the GDLS on serious injury crashes. The source of the injury crash data was New Zealand's Health Information Services' national public hospital inpatient morbidity data files for the years 1979-1992 inclusive. We disaggregated the occupant data into three age groups 15-19 years, 20-24 years, and persons 25 years of age or older and compared their trends in injury. In order to determine whether the incidence of motor vehicle crashes was simply following trends in other injury events we also included two 15-19 year old non-traffic injury comparison groups. Using time series analyses we showed that the introduction of the GDLS was closely followed by substantial reductions in car crash injuries for all age groups, especially 15-19 year olds (23% reduction). After considering effects for older occupants we speculate that the effect is likely to be substantially less than 23%. An analysis of licensure data suggests that the reduction in crashes may, in large part, be attributable to an overall reduction in exposure.