The effects of graduated driver licensing on hospitalization rates and charges for 16-and 17-year-olds in North Carolina

OBJECTIVE: To mitigate the high risk of motor vehicle crashes for young beginning drivers, over 40 states and the District of Columbia have implemented graduated driver licensing (GDL) systems that gradually and systematically ease teen drivers into higher risk driving conditions. Evaluations of GDL programs using motor vehicle crash data have demonstrated marked declines in crashes. The objective of this study is to examine the association between the implementation of the North Carolina GDL program and the rate of hospitalization, as well as hospital charges, for 16-and 17-year-old drivers. METHODS: Data were obtained from the North Carolina Hospital Discharge Database for the 26 months before and 46 months after the December 1, 1997, implementation of the GDL program. ARIMA interrupted time series analyses were used to model monthly hospitalization rates, controlling for the hospitalization rates of 25-to 54-year-old drivers. ARIMA analyses were also used to determine whether changes occurred in monthly total hospital charges. RESULTS: Among the 568 16-year-old hospitalized drivers, GDL was associated with a 36.5% decline in the hospitalization rate per population and a 31.2% decline in the total monthly driver hospitalization charges. Although a 12% reduction in the rate of hospitalizations was observed among the 615 17-year-old drivers, the analysis lacked sufficient power to be statistically reliable. No consistent change was observed in the 16-year-old driver total monthly hospital charges. CONCLUSIONS: The North Carolina GDL program was associated with a marked decline in the rate of hospitalizations and hospital charges for 16-year-old drivers. Following the implementation of GDL, over $650,000 in hospital charges have been averted each year for 16-year-old drivers. Analyses suggest these reductions were primarily the result of reduced exposure rather than an improvement in teen driving.     

Michigan's graduated driver licensing program: evaluation of the first four years

INTRODUCTION: To evaluate the four-year outcome of Michigan's graduated driver licensing (GDL) program, motor-vehicle crash data for 16-year-old drivers in 1996 (pre-GDL), and 1998-2001 (post-GDL) were analyzed. METHOD: Relative risks and 95% confidence intervals for several crash types were computed, and pre-post-GDL population-based crash rates were compared. Reductions in crash risks among 16-year-olds previously found in 1998 and 1999 were generally maintained in 2000 and 2001. RESULTS: Reductions in crash risk among 16-year-olds from 1996 to 2001 were 29% for all, 44% for fatal, 38% each for nonfatal-injury and fatal-plus-nonfatal-injury, 32% for day, 31% for evening, 59% for night, 32% for single-vehicle, and 28% for multi-vehicle crashes. Even after adjusting for more general population-wide changes among drivers 25 years and older that might have contributed to changes in 16-year-old crash risk, reductions remained impressive (19% for all crashes in 2001). IMPACT ON INDUSTRY: As one approach to reducing teenage motor-vehicle morbidity and mortality, GDL remains promising.     

Tracking progress in teenage driver crash risk in the United States since the advent of graduated driver licensing programs

IntroductionThis study examined U.S. teenagers' crash rates since 1996, when the first graduated driver licensing (GDL) program in the United State was implemented.MethodsPassenger vehicle driver crash involvement rates for 16–19 and 30–59 (middle-aged) year-olds were examined, using data from the Fatality Analysis Reporting System, National Automotive Sampling System General Estimates System, Census Bureau, and National Household Travel Surveys.ResultsPer capita fatal and police-reported crash rates in 2012 were lower for 16 year-olds than for middle-aged drivers but older teenagers' rates were higher. Mileage-based fatal and police-reported crash rates in 2008 were higher for teenagers than for middle-aged drivers and higher for 16–17 year-olds than for older teenagers. In 1996–2012, teenagers' per capita fatal and police-reported crash rates declined sharply, especially for 16–17 year-olds, and more so than for middle-aged drivers. Substantial declines also occurred in teenagers' mileage-based fatal and police-reported crash rates from 1995–96 to 2008, generally more so than for middle-aged drivers. Regarding factors in fatal crashes in 1996 and 2012, proportions of young teenagers' crashes occurring at night and with multiple teenage passengers declined, more so than among older teenagers and middle-aged drivers. The proportion of fatally injured drivers who had been drinking declined for teenagers but changed little for middle-aged drivers. Improvements were not apparent in rates of driver errors or speeding among teenage drivers in fatal crashes.ConclusionsTeenage drivers' crash risk dropped during the period of implementation of GDL laws, especially fatal crash types targeted by GDL. However, teenagers' crash risk remains high, and important crash factors remain unaddressed by GDL.Practical applicationsAlthough this study was not designed to examine the role of GDL, the results are consistent with the increased presence of such laws. More gains are achievable if states strengthen their laws.     

Does the Maryland graduated driver licensing law affect both 16-year-old drivers and those who share the road with them?

PROBLEM: To assess effects of the 1999 Maryland graduated driver licensing (GDL) law on both 16-year-old drivers and other road users. METHOD: Calculation and comparison of crash involvement rates and non-fatal injury rates pre-GDL (1996-1998) and post-GDL (2001-2003) by type of road user, per population, and per licensed driver, with adjustment for trends among 30-59-year-old drivers. RESULTS: Post-GDL, prevalence of licensure decreased 24% among 16-year-olds, and rates of 16-year-old drivers involved in crashes significantly decreased per 16-year-old population (corrected rate ratio (RRc) 0.82; 95% CI (0.71, 0.96)). A significant decrease also was observed for non-fatal injuries per 16-year-old population among 16-year-old drivers involved in crashes (RRc 0.63; 95% CI (0.41, 0.98)). Similarly, decreases, albeit not statistically significant, were observed among their passengers and other vehicle occupants. Per 16-year-old licensed driver, a slight non-significant increase was observed in crash involvement rates; non-fatal injury rates per 16-year-old licensed driver suggest decreased risk (non-significant) among 16-year-old drivers, their passengers, and other vehicle occupants. SUMMARY: Maryland's GDL delayed licensure and reduced crashes and non-fatal injuries among 16-year-old drivers per population. Trends in injuries among other road users involved in crashes with 16-year-old drivers were suggestive of a benefit from GDL, although observed decreases were not significant. Per licensed driver, findings were not significant, but suggested little change in crash involvement and decreased non-fatal injuries. Because one-third fewer 16-year-olds were licensed post-GDL, these results may suggest a selection effect in licensure. IMPACT ON INDUSTRY: Because Maryland had nighttime restrictions for new drivers before 1999, this study suggests other components of GDL are beneficial for drivers and possibly for other road users. States with weak GDL laws should strongly consider revising them.     

Evaluation of California's graduated driver licensing program

Problem: California's graduated driver licensing (GDL) program was implemented to reduce the high crash risk of teenage drivers. The program enhancements made in 1998 were evaluated in this study using methods that rule out the noticeable downward trend in California teen's fatal/injury crash rates as a possible explanation for any observed crash reductions that could otherwise be mistaken for program effects. Method: Monthly per capita fatal/injury crash rates for 15-to-17-year-olds and proportional representations of 16–17-year-olds' nighttime and passenger crashes were analyzed using intervention time series analysis. Results: After removing trend, seasonality, and transition effects in the data, no overall reductions in fatal/injury crashes for 15–17-year-olds or 16-year-olds (separately) were found to be associated with the 1998 program enhancements, suggesting no overall exposure reduction effect of the longer instruction permit period nor increased competency associated with the higher number of required practice hours. However, the 12-month nighttime and 6-month passenger restrictions were found to be associated with annual savings of 55 and 816 fatal/injury crashes, respectively. Discussion: Finding no overall impact of the 1998 GDL enhancements was not surprising given findings of an earlier survey suggesting that California teens and parents were largely already practicing program requirements prior to implementation and were not fully complying with the program requirements afterwards. Though the observed crash savings associated with the restrictions were of modest size, this is the first study to evidence a direct positive impact of the passenger restriction component of GDL programs. Larger reductions could be realized if the nighttime restriction started earlier and parents/law enforcement could be motivated to better enforce these restrictions. Impact on Industry: The findings provide support for passenger and nighttime restriction components of GDL programs.     

National evaluation of the effect of graduated driver licensing laws on teenager fatality and injury crashes

ProblemAutomobile crashes remain a prominent cause of death and injury for teenagers in the United States. While it is generally agreed that graduated drivers licensing (GDL) influences crash rates, it is unclear which components have the strongest effect on any specific types of crashes.MethodWe analyze the relative effect of different stages of GDL on teenage fatal and injury crash risk via a negative binomial generalized linear model with random state effects. Overall, nighttime, and crashes with multiple teenage passengers are considered.ResultsThe strongest effects are seen by 16-year-olds, for which a strict permit stage is associated with a 58% reduction in fatal crash risk over a lenient permit stage. Similar reductions are seen for injury crashes. The intermediate stage, involving nighttime and passenger restrictions, is associated with a 44% reduction in fatalities but has relatively little effect on injury crashes. The strongest effects are generally seen for passenger crashes, followed by nighttime, and then overall crashes.Impact on IndustryThis study identifies stronger relationships between GDL and crash risk than has previously been discovered and captures the relative effects of permit and intermediate licensing restrictions, two high-level components of GDL which differ in intent and implementation.     

Progress in teenage crash risk during the last decade

OBJECTIVE: The purpose of the present study was to examine the most recent data on teenagers' fatal and nonfatal crashes in the United States to determine current crash rates as well as changes in crash rates during the past decade METHODS: Data for calendar years 1996 and 2005 were extracted for fatal crashes from the Fatality Analysis Reporting System and for police-reported crashes from the National Automotive Sampling System/General Estimates System. To calculate crash rates, population data were obtained from the Census Bureau, and mileage data were obtained from the 2001 National Household Travel Survey RESULTS: During 2001-02, the latest year for which mileage data are available, 16 year-old drivers had higher fatal and nonfatal crash rates per mile traveled than all but the very oldest drivers. However, fewer 16 year-olds typically are licensed to drive and they drive fewer miles per year than all but the oldest drivers. Thus, their fatal and nonfatal crash rates per population in 2005 were lower than among other teenagers and among drivers 20-29. During the past decade the most progress has been made in reducing crashes among the youngest drivers. Between 1996 and 2005 both fatal and police-reported crashes per population declined about 40% for 16 year-old drivers, compared with about 25% for 17 year-old drivers and 15-19% for 18 year-old drivers. The greatest reductions for 16 year-olds occurred in nighttime crashes, alcohol-related fatal crashes, and fatal crashes involving multiple teenage passengers. CONCLUSIONS: Substantial progress has been made in reducing fatal and nonfatal crashes per population among 16 year-old drivers. Although this study was not designed to examine the role of graduated licensing, the results are consistent with the increased presence of such laws, many of which restrict nighttime driving and driving with teenage passengers. IMPACT ON INDUSTRY: Restrictions on nighttime driving and driving with teenage passengers should be made a part of all states' graduated licensing systems. Historically, 16 year-olds have had the highest crash risk per licensed driver and per mile traveled. Given the dramatic reductions in per population crash rates among 16 year-olds, it is possible that their per mile and per licensed driver rates also have declined and may no longer be as elevated relative to other ages. However, shortcomings in the licensed driver data and a lack of recent mileage data hamper our ability to examine these issues. If we are to continue to provide a yardstick against which we can measure progress among the youngest drivers, immediate steps need to be taken to restore the availability of reliable exposure data.     

Graduated driver licensing in the United States: evaluation results from the early programs

BACKGROUND: Seventeen states enacted graduated driver licensing (GDL) programs that were implemented from 1996 through 1999 and for which evaluations are of interest. METHODS: We received evaluation results reported for six states for which data were available. Summarizing results is difficult in other than the most global terms because of differences in pre-GDL programs, differences in GDL programs, and differences in evaluation methodology. RESULTS: All states identified some crash reduction among teen drivers following GDL implementation. This positive effect was observed across different geographic regions, and with different GDL programs. Simple counts are down-fewer teens are experiencing crashes and becoming injured. After calculating crash rates to adjust for changes over time in populations or licensed drivers, reductions generally were still found. Population-adjusted risks of injury/fatal crash involvement of 16-year-old drivers in Florida and Michigan were reduced by 11% and 24%, respectively. Population-adjusted risks of any crash involvement of 16-year-old drivers in Michigan and North Carolina were reduced by 25% and 27%, respectively. Reductions in night (restricted hours) crash risk were impressive in Florida, Michigan, and North Carolina. A comparison state design was only possible in the Florida evaluation, and results showed greater crash reductions under GDL. Change-point analyses of Michigan's crash data trends over time provided additional support of GDL's effectiveness in reducing crashes. DISCUSSION: Taken as a whole, and including the preliminary findings from California, Ohio, and Pennsylvania, these reports demonstrate the early effectiveness of GDL in reducing the crash risk of teen drivers. The impact of these studies and others to come will guide future research, practice, and policy.     

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

Introduction: Graduated driver licensing (GDL) systems have been shown to reduce rates of crashes, injuries, and deaths of young novice drivers. However, approximately one in three new drivers in the United States obtain their first driver’s license at age 18 or older, and thus are exempt from most or all provisions of GDL in most states. Method: In July 2015, the state of Indiana updated its GDL program, extending its restrictions on driving at night and on carrying passengers during the first 6 months of independent driving, previously only applicable to new drivers younger than 18, to all newly-licensed drivers younger than 21 years of age. The current study examined monthly rates of crashes per licensed driver under the affected conditions (driving at night and driving with passengers) among Indiana drivers first licensed at ages 18, 19, and 20 under the updated GDL system compared with drivers licensed at the same ages under the previous GDL system. We used Poisson regression to estimate the association between the GDL system and crash rates, while attempting to control for other factors that might have also influenced crash rates. We used linear regression to estimate the association between the GDL system and the proportion of all crashes that occurred under conditions restricted by the GDL program. Results: Results showed, contrary to expectations, that rates of crashes during restricted nighttime hours and with passengers were higher among drivers licensed under the updated GDL system. This mirrored a statewide increase in crash rates among drivers of all ages over the study period and likely reflected increased overall driving exposure. The proportions of all crashes that were at night or with passengers did not change. Practical Applications: More research is needed to understand how older novice drivers respond when GDL systems originally designed for younger novice drivers are applied to them.     

A national evaluation of the nighttime and passenger restriction components of graduated driver licensing

Introduction

The high crash rate of youthful novice drivers has been recognized for half a century. Over the last decade, graduated driver licensing (GDL) systems, which extend the period of supervised driving and limit the novice's exposure to higher-risk conditions (such as nighttime driving), have effectively reduced crash involvements of novice drivers.

Method

This study used data from the Fatality Analysis Reporting System (FARS) and the implementation dates of GDL laws in a state-by-year panel study to evaluate the effectiveness of two key elements of GDL laws: nighttime restrictions and passenger limitations.

Results

Nighttime restrictions were found to reduce 16- and 17-year-old driver involvements in nighttime fatal crashes by an estimated 10% and 16- and 17-year-old drinking drivers in nighttime fatal crashes by 13%. Passenger restrictions were found to reduce 16- and 17-year-old driver involvements in fatal crashes with teen passengers by an estimated 9%.

Conclusions

These results confirm the effectiveness of these provisions in GDL systems. Impact on Public Health. States without the nighttime or passenger restrictions in their GDL law should strongly consider adopting them.

Impact on Industry

The results of this study indicate that nighttime restrictions and passenger limitations are very important components of any GDL law.     

Passenger effects on teenage driving and opportunities for reducing the risks of such travel

OBJECTIVES: To review the research evidence concerning the effects of passengers on teenage driving and crash involvement, and to explore ways to reduce negative effects. METHODS: Review of the international literature on these topics. RESULTS: Passenger presence increases crash risk for teenage drivers, especially when the passengers are other teenagers and especially when they are male. Female passengers do not have the same effects. Teenagers are more susceptible to peer influences than adults. The combination of passenger-induced distraction and driving inexperience can disrupt driving behavior, and there is evidence that teenage driver risk taking increases in vehicles with multiple teenagers. Possible ways to reduce the resulting crash problem include altering the in-vehicle behavior of teenagers or influencing their selection of travel partners. Legal restrictions on passengers with teenage drivers have been found effective in reducing the crash problem. Parental monitoring of teenage driving behavior, and programs aimed at teenagers themselves, could be other options but their efficacy is unproven. It currently is unknown why female passengers have a different effect than males or if that might offer clues about future interventions. CONCLUSIONS: Despite passenger restrictions in the majority of states, 42% of 16- and 17-year-old drivers in fatal crashes in 2005 were transporting teenagers with no adults in the vehicle; 61% of teenage passenger deaths (1,222 in 2005) occurred in vehicles driven by other teenagers. Wider application of passenger restrictions is indicated. IMPACT ON INDUSTRY: Ways to make passenger restrictions more effective are needed, and other techniques for reducing this major problem need development and testing.     

Factors related to seat belt use among fatally injured teenage drivers

PROBLEM: In the United States, teenage drivers have a higher crash risk and lower observed seat belt use than other age groups. METHOD: Seat belt use was examined for teenage (16-19 years) drivers who were fatally injured in traffic crashes occurring in the United States during the years 1995-2000. Vehicle, driver, and crash factors potentially related to belt use were examined. State differences in belt use rates among fatally injured teenage drivers were related to states' observed belt use rates for all ages and other state-level variables. RESULTS: During 1995-2000, mean belt use was 36% among fatally injured teenage drivers and 23% among fatally injured teenage passengers. One of the strongest predictors of higher belt use for both drivers and passengers was whether the crash occurred in a state with a primary seat belt law. Belt use rates for 1995-2000 for fatally injured teenage drivers ranged from 20% or less in six states to more than 60% in two states. States with the highest use rates were those with strong primary belt use laws and those with high rates of observed belt use for all ages. Lower belt use among fatally injured teenage drivers was associated with increasing age; male drivers; drivers of SUVs, vans, or pickup trucks rather than cars; older vehicles; crashes occurring late at night; crashes occurring on rural roadways; single vehicle crashes; and drivers with BACs of 0.10 or higher. Teenage driver belt use declined as the number of teenage passengers increased, but increased in the presence of at least one passenger 30 years or older. IMPACT ON TRAFFIC SAFETY: It is suggested that to increase teenage belt use, states should enact strong primary belt use laws and mount highly publicized efforts to enforce these laws. Graduated driver licensing systems should incorporate strong provisions that require seat belt use by teenage drivers and passengers.     

Effects of the California graduated driver licensing program

PROBLEM: On July 1, 1998, in an effort to ameliorate the problem of high teenage driver crash rates, California implemented a graduated driver licensing system (GDLS). METHOD: Data on injury crashes of 16- and 17-year-old drivers from a pre-GDLS year were compared with data from two post-GDLS years. Per-capita crash rate ratios were adjusted for changes in crash rates of 25- to 34-year-old drivers, who were unaffected by the GDLS. Prevented numbers and 95% confidence intervals were estimated. RESULTS: Fatal or severe injury crash rates were significantly lower during each of the two post-GDLS years (adjusted rate ratios (RR)=0.72 and 0.83, for 2000 vs. 1997 and 2001 vs. 1997, respectively). Significant rate reductions were observed for all crash types, particularly for struck object (RR=0.71 and 0.80, for 2000 vs. 1997 and 2001 vs. 1997, respectively) and non-collision (RR=0.63 and 0.72, for 2000 vs. 1997 and 2001 vs. 1997, respectively). Minor injury crash rates were also lower during post-GDLS years (RR=0.87 and 0.90, for 2000 vs. 1997 and 2001 vs. 1997, respectively). Percent reductions were notably larger during the hours of the late night driving restriction (midnight-5 a.m.) (RR=0.79 and 0.87, for 2000 vs. 1997 and 2001 vs. 1997, respectively). SUMMARY: The implementation of the California GDLS was followed by large reductions in the rate of injury-producing motor-vehicle crashes. IMPACT ON INDUSTRY: This evaluation supports previous evidence that GDLS is an effective countermeasure to adolescent motor-vehicle crashes and their associated injuries. States with a traditional licensing system may prevent adolescent driver crashes by adopting a GDLS. Future studies should examine factors that influence teenager compliance with GDLS provisions and identify approaches to improving compliance.     

California's graduated driver license law: Effect on teenage drivers' deaths through 2005

PROBLEM: While many researchers believe Graduated Driver Licensing (GDL) laws save lives by imposing restrictions and delayed licensure on drivers under age 18, longer term effects on older teenagers have not been studied. METHOD: The effects of California's strict GDL law on deaths of drivers ages 16-19 were analyzed for 1995-2005 using Incidence Rate Ratios (IRR) and Auto-Regressive Integrated Moving Average (ARIMA) time series analysis of Fatality Analysis Reporting System mortality data. RESULTS: The two methods yielded similar results. IRR analysis found California 16-year-old drivers subject to the GDL experienced a 15% fatality decline (95% CI, 0.70-0.99), while 18 year-old drivers experienced a 15% increase (95% CI, 1.02-1.27). ARIMA analysis found 16 year-old drivers experienced a near-significant 20% fatality decline (p=0.07), while 18 year-olds experienced a 24% increase (p=0.01). Unlicensed teenage drivers and older teen drivers driving alone and transporting teenage passengers suffered significant fatality increases. SUMMARY AND DISCUSSION: California's GDL may negatively affect older teenagers and other driver subpopulations and merits reevaluation.     

Characteristics of teens-with-teens fatal crashes in the United States, 2005–2010

BackgroundMore than 40% of fatal crashes of 16- and 17-year-old drivers occur when transporting teenagers. Characteristics of this predominant crash type and prevention possibilities are described, based on data from fatal crashes in the United States during 2005–2010.ResultsFifty-seven percent of 16- and 17-year old drivers in fatal crashes had at least one passenger. Most commonly, all passengers were ages 13–19 (42% of all drivers and 73% of those with passengers). Of fatal crashinvolved drivers with teenage passengers and no passengers of other ages, 56% had one passenger, 24% had two, and 20% had three or more. Most frequently, passengers were the same sex and within one year of the driver. Risk factors involving speeding, alcohol use, late-night driving, lack of a valid license, seat belt non-use, and crash responsibility were more prevalent with teenage passengers than when driving alone, and the prevalence of these factors increased with the number of teenage passengers. Many risk factors were most prevalent with passengers ages 20–29, although few crashes had this occupant configuration. Risk factors were least prevalent with a passenger 30 or older.DiscussionFatal crashes of 16- and 17-year-old drivers with teen passengers are a common crash scenario, despite passenger restrictions in 42 states and the District of Columbia during some or all of the study period. The proportion of these fatal crashes decreased slightly from 46% in 1995 (pre-GDL) to 43% in 2010 and showed no signs of decreasing during the six-year study period (range 41% to 43%).Practical applicationsExisting passenger restrictions are relatively weak and could be strengthened. Fatal crashes involving teen passengers, especially multiple passengers, are more likely to involve alcohol, late-night driving, driver error, and invalid licensure, so stepped-up enforcement of existing laws involving these behaviors might reduce the prevalence of such crashes.     

Temporal patterns of crashes of 16-to 17-year-old drivers in Fairfax County, Virginia

OBJECTIVE: To develop a better understanding of the frequency and characteristics of teenage driver crashes occurring during school commute times. METHOD: Data were obtained from police reports of crashes involving drivers ages 16-17 that occurred between September 2001 and August 2004 in Fairfax County, Virginia. Temporal patterns and other characteristics of crash involvement during the school year were examined, and crashes during school commute times were compared with those at other times. RESULTS: Teenage driver crash involvement spiked during weekday school commute times. Compared with other times, crashes during school commute times were significantly more likely to involve multiple vehicles but less likely to result in injuries or involve drivers who were male, made driving errors, or had been drinking alcohol. Crashes during school commute times were more likely to involve more than one teenage driver and occur close to schools. CONCLUSIONS: Crashes involving teenage drivers are prevalent during school commute times. Many of these crashes involve multiple teenage drivers and occur near schools. Schools and communities should consider programs and policies that reduce teenage driving to school and enhance the safety of teenagers that do drive.     

The legal minimum drinking age in texas: Effects of an increase from 18 to 19

Effects on motor vehicle crash involvement of raising the legal drinking age in Texas from 18 to 19 were examined, using an interrupted time-series design. Rates of single-vehicle-nighttime (SVN) and non-SVN crashes per 100,000 licensed drivers from 1978 through 1984 were examined for three levels of crash severity (serious injury, minor injury, property damage only) and four age groups (16–17, 18, 19–20, 21 and over). Results revealed significant reductions in SVN crashes for the 18-year-old target population across all levels of crash severity: serious injury, down 10.8% ; minor injury, down 14.3% ; and property damage only, down 12.8%. In comparison, no significant changes in SVN crashes among drivers age 21 and over were found. When the effects of macroeconomic conditions on crash rates were controlled statistically, no change in the estimated effect of the legal age law was seen. It is clear that the 1-year increase in legal age in Texas had a significant effect on youth crash involvement.     

Exposure-based assessment of the effectiveness of Michigan’s graduated driver licensing nighttime driving restriction

The objective of the study is to assess the effectiveness of Michigan’s graduated driver licensing (GDL) program in terms of nighttime driving restriction. The research uses the quasi-induced exposure technique to capture and represent the exposure and accident risk change of the impacted driver groups due to the implementation of the GDL program. Six years of Michigan accident data were used, including three years before the GDL implementation and three years after. The effectiveness of Michigan’s GDL program in terms of nighttime driving is reflected in several dimensions: for the impacted drivers (16- and 17-year-olds), there is a significant reduction of exposure compared to the reference group and a decrease in the relative accident involvement ratio (thus a reduced accident risk); and examination of time of day distributions of impacted teenage drivers shows that there is a conspicuous percentage drop of impacted teenage drivers at the point where the nighttime curfew starts. With the implementation of the GDL program, the affected group tends to drive increasingly more in the several hours prior to the restricted time period to avoid violating the curfew law. As opposed to the traditional exposure measurements such as population or licensed drivers, quasi-induced exposure technique has the capability of depicting the accident propensity and quantifying exposure change from different age groups.     

Impact of Georgia's teenage and adult driver responsibility act: 15-year follow-up

Objective: This study was designed to investigate the 15-year impact of Georgia's graduated drivers' licensing (GDL) law, the “Teenage and Adult Driver Responsibility Act” (TADRA), on fatality crashes among young drivers.

Methods: Fatality Analysis Reporting System (FARS) data for Georgia and Census denominators were used to determine fatal crash rates (FCRs) of drivers ages 16 through 19 who passed through the Georgia GDL system during the 5.5 years prior to through 15.5 years after TADRA's implementation. FCRs of younger drivers were compared to those of drivers ages 20–54 and 55–75 and compared by gender. Attention was given to speeding- and alcohol-related crashes, 2 foci of TADRA.

Results: The decline in FCRs has been maintained and even increased through 15.5 years after passage of the law. Extending the curfew and further limiting passengers (passed in 2001) and driver's education and supervised driving requirements (added in 2007) may have contributed. The greatest declines were among 16- and 17-year-olds; most of the gains were among male drivers. The changes were greatest for alcohol- and speeding-related crashes. Those 18 and 19 years old did not demonstrate an increase in FCR over the period studied.

Conclusion: Georgia's graduated licensing law, TADRA, has maintained and in some instances increased in effectiveness over the 15.5 years since its inception. Though national research suggests that GDL laws are associated with increased crash rates among 18- to 19-year-old drivers, this has not occurred in Georgia; 18- and 19-year-olds demonstrated no change or reductions in FCR over the 20.5-year period evaluated. Declines were greatest for those driving behaviors targeted by the law.