The role of inexperience in motorcycle crashes among novice and returning motorcycle riders.

OBJECTIVES: To examine the crash trends of younger novice and older novice/returning motorcycle riders. METHODS: We used a linked database of North Carolina crash and licensing data from 1991 through 2018 that included 103,142 younger novice and 98,540 older novice/returning motorcycle riders. We examined the percent of riders who crashed each month after obtaining a motorcycle license. RESULTS: Crash rates peak for both younger novice and older novice/returning motorcycle riders immediately after licensure. Crash rates decline rapidly, and the rate of decrease resembles a power function. The improvement rate (IR) for younger novice riders is 0.42; that is, the crash rate for younger novices declines by approximately 42% as experience doubles. CONCLUSION: The crash curve for novice motorcyclists is similar to that of novice car drivers and is consistent with a learning process. PRACTICAL APPLICATIONS: The crash trends of novice motorcycle riders indicate that current training, licensing, and educational efforts are not adequately preparing new riders. Additional efforts to develop more effective training, and research to inform a well-calibrated graduated licensing process for new riders are needed.

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.

Crashes of novice teenage drivers: characteristics and contributing factors.

OBJECTIVE: The initial months of licensure are especially hazardous for teenagers. Factors leading to crashes of novice 16-year-old drivers were identified. METHOD: Sixteen year-olds in Connecticut who were involved in nonfatal crashes during the first 8 months of licensure were interviewed, and police crash reports were examined. Crash types and contributing factors were identified. RESULTS: Three-fourths of the crash-involved teenagers were at fault. Their crashes resulted primarily when they ran off the road, rear ended another vehicle, or collided with another vehicle that had the right-of-way. Three factors contributed about equally to their crashes: failing to detect another vehicle or traffic control, speeding, and losing control of the vehicle or sliding. Slippery roads also were an important factor. Most failures to detect another vehicle or traffic control involved not looking thoroughly, distraction, or inattention. DISCUSSION: Based on the findings, potential countermeasures for reducing crashes of novice teenage drivers include adequate practice driving, in-vehicle monitoring devices, and electronic stability control. IMPACT ON INDUSTRY: More than half of the nonfatal, at-fault crashes of newly licensed 16-year-old drivers involved more than one contributing factor including speed, loss of control, and slippery roads. Efforts to reduce teenage crashes should focus on these factors.

Effectiveness and driver acceptance of the Honda belt reminder system.

OBJECTIVE: Prior research suggests that vehicle-based seat belt reminder systems can produce moderate increases in belt use rates. However, these findings were based on a limited set of Ford vehicles in one geographic location. As more vehicles with reminder systems enter the market, it is important to determine their effectiveness as well as acceptance by consumers. The present study investigated the effectiveness of Honda's belt reminder system. METHODS: Driver belt use was observed unobtrusively as drivers brought their Honda vehicles to dealerships for service. Drivers also were asked to complete a mail-in survey designed to elicit their experience with the system. RESULTS: Belt use was significantly higher among drivers of vehicles with belt reminders compared with drivers of vehicles without reminders (90 vs. 84 percent). Use rates in vehicles with reminders were higher among both male and female drivers and in all vehicle types observed. Drivers of the Honda vehicles with belt reminders viewed the system very favorably, and nearly 90 percent said they would want one in their next vehicle. The reminder was perceived to be most effective by part-time belt users; 81 percent of part-time users said they now use belts more often, compared with 32 percent of respondents who said they always use belts and 18 percent who use belts occasionally. CONCLUSION: Belt reminders in Honda as well as Ford vehicles are increasing. Although the increase is moderate (5.6 percentage points), on a national level it could have prevented at least 736 driver deaths in 2004.

Factors leading to older drivers' intersection crashes.

OBJECTIVES: Older drivers are overinvolved in intersection crashes compared with younger drivers, but the reasons are not clearly understood. The purpose of the present study was to identify the factors that lead to older drivers' intersection crashes. METHOD: Study participants were composed of two groups of older drivers -- ages 70-79 (n = 78) and 80 and older (n = 76) -- and a comparison group of drivers ages 35-54 (n = 73); all were at fault in intersection crashes involving nonfatal injuries. Police crash reports, telephone interviews with at-fault drivers, and photographs of intersections were used to determine the kinds of driver actions and errors that led to the intersection crashes. RESULTS: Drivers 80 and older had fewer rear-end crashes than drivers ages 35-54 and 70-79, and both groups of older drivers had fewer ran-off-road crashes than drivers ages 35-54. Crashes where drivers failed to yield the right-of-way increased with age and occurred mostly at stop sign-controlled intersections, generally when drivers were turning left. The reasons for failure-to-yield crashes tended to vary by age. Compared with drivers ages 35-54 and 80 and older, drivers ages 70-79 made more evaluation errors -- seeing another vehicle but misjudging whether there was adequate time to proceed. In contrast, drivers 80 and older predominantly failed to see or detect the other vehicle. Drivers ages 35-54 also tended to make search errors, but theirs were due more often to distraction. CONCLUSIONS: Factors leading to intersection crashes vary with age, even between two age groups of older drivers. Because the number of older drivers is projected to increase, it is important to identify ways to reduce the frequency and severity of their intersection crashes. Roundabouts and protected left turn lanes at signalized intersections may help to reduce failure-to-yield crashes at intersections, especially among older drivers. Crash avoidance systems may help to reduce crashes for drivers of all ages, but most systems have not been thoroughly investigated using real-world crash data.

The effects of minimum legal drinking age 21 laws on alcohol-related driving in the United States.

OBJECTIVE: To examine trends in alcohol consumption and alcohol-related crashes among people younger than 21 in the United States and to review evidence on the effects of minimum legal drinking age (MLDA) laws. METHODS: Trends in alcohol-related crashes and alcohol consumption among young people were examined, and studies on the effects of lowering and raising the drinking age were reviewed. RESULTS: MLDA laws underwent many changes during the 20th century in the United States. Since July 1988, the MLDA has been 21 in all 50 states and the District of Columbia. Surveys tracking alcohol consumption among high school students and young adults found that drinking declined since the late 1970 s, and most of the decline occurred by the early 1990 s. These were the years when states were establishing, or reinstating, a MLDA-21. Among fatally injured drivers ages 16-20, the percentage with positive BACs declined from 61% in 1982 to 31% in 1995, a bigger decline than for older age groups; declines occurred among the ages directly affected by raising MLDAs (ages 18-20) and among young teenagers not directly affected (ages 16-17). Almost all studies designed specifically to gauge the effects of drinking age changes show MLDAs of 21 reduce drinking, problematic drinking, drinking and driving, and alcohol-related crashes among young people. Yet many underage people still drink, many drink and drive, and alcohol remains an important risk factor in serious crashes of young drivers, especially as they progress through the teenage years. Stepped-up enforcement of MLDA and drinking and driving laws can reduce underage drinking. Recent efforts to lower MLDAs to 18 and issue licenses to drink upon completion of alcohol education have gained local and national media attention. There is no evidence that alcohol education can even partially replace the effect of MLDA-21. CONCLUSIONS: The cause and effect relationship between MLDAs of 21 and reductions in highway crashes is clear. Initiatives to lower the drinking age to 18 ignore the demonstrated public health benefits of MLDAs of 21. IMPACT ON INDUSTRY: Lowering the drinking age to 18 will increase highway crash deaths among young people.

Effects of in-vehicle monitoring on the driving behavior of teenagers.

OBJECTIVES: The objective was to determine if teenage driving behavior improves when a monitoring and feedback device is installed in the teen's vehicle. METHODS: Vehicles of 85 teenage drivers were fit with a device that detected all instances of sudden braking/acceleration, speeding, and nonuse of seat belts. Drivers were assigned randomly to one of four research groups, differing in whether or not an alert sounded in the vehicle and whether or not parents were given access to websites containing notification records. Time trends in event rates per mile traveled were compared using Poisson regression. RESULTS: Seat belt use improved when violations were reported to the parent websites, and improved even more when in-vehicle alerts were activated. Consistent reductions in speeding were achieved only when teenagers received alerts about their speeding behavior, believed their speeding behavior would not be reported to parents if corrected, and when parents were being notified of such behavior by report cards. CONCLUSIONS: Electronic monitoring of teenage drivers can reduce the incidence of risky behavior, especially seat belt nonuse. More complicated behavior is more difficult to change, however. IMPACT ON INDUSTRY: Parent participation is key to successful behavioral modification, but it is yet to be determined how best to encourage such participation.

Making the most of the worst-case scenario: should belt-positioning booster seats be used in lap-belt-only seating positions?

OBJECTIVE: Examine real-world crash injury data to determine whether children seated with lap belts only are better protected with or without belt-positioning booster seats. METHODS: Crash injury rates among booster-age children were examined for three restraint categories: lap belt only, belt-positioning booster seat with lap belt, and booster seat with lap/shoulder belt. Data were drawn from the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) and the Partners for Child Passenger Safety (PCPS) crash surveillance system for years 1997-2006 and 1998-2006, respectively. Main outcome measures were the percentage of crash-involved booster-age children with moderate or greater injury (maximum abbreviated injury score [MAIS] 2+). RESULTS: The estimated risk of MAIS 2+ injury among children restrained with lap belts and boosters was 0.12 percent (NASS-CDS) and 0.96 percent (PCPS), compared with 1.21 and 1.74 percent, respectively, for lap belts only. This difference was not significant due to small numbers of children in lap belts with boosters. In PCPS, children restrained by lap/shoulder belts and boosters had lower injury risk than children restrained by lap belts, with or without boosters. CONCLUSIONS: Although data for children secured in lap belts with boosters are limited, the results suggest that boosters are not harmful. This finding is inconsistent with the current recommendation that booster seats not be used when children must be buckled with lap belts only. Data also confirm that booster seats with lap/shoulder belts remain the optimal protection for booster-age children.