Keli A. Braitman

Effects of Age and Experience on Young Driver Crashes: Review of Recent Literature

Objective: Although both youth and inexperience contribute to the elevated crash rates of teenage drivers, the relative contribution of these factors has not been firmly established. Methods: A review was undertaken of eleven recent (1990 or newer) studies that tried to separate the crash effects of age and experience, represented by length of licensure. Results: The weight of evidence is that age and experience have important, independent effects on crash risk, even after differences in driving mileage are accounted for. The studies consistently found that teenage drivers had dramatically higher crash rates than older drivers, particularly drivers older than 25, after controlling for length of licensure. Studies that distinguished 16-year-olds found that crash rates for novice 16-year-olds were higher than rates for novice 17-year-olds, but crash rates for novice 17-year-olds were not consistently higher than rates for novice 18- to 19-year-olds. With regard to experience, the weight of evidence suggests a steep learning curve among drivers of all ages, particularly teenagers, and strong benefits from longer licensure. Of the studies that attempted to quantify the relative importance of age and experience factors, most found a more powerful effect from length of licensure. Conclusions: The findings lend support to delaying licensure among teenagers in the United States, where licensure commonly is allowed at age 16, and to graduated licensing systems that phase in unsupervised driving during high-risk situations as teenagers gain independent driving experience.

Graduated Licensing Laws and Fatal Crashes of Teenage Drivers: A National Study

Objectives: The objective of the current study was to quantify the effects of the strength of US state graduated driver licensing laws and specific licensing components on the rate of teenage driver fatal crash involvements per 100,000 teenagers during 1996–2007. The strengths of state laws were rated good, fair, marginal, or poor based on a system developed previously by the Insurance Institute for Highway Safety. Methods: Analysis was based on quarterly counts of drivers involved in fatal crashes. Associations of overall ratings and individual licensing components with teenage crash rates were evaluated using Poisson regression, with the corresponding fatal crash rate for drivers ages 30–59 controlling for state- or time-dependent influences on crash rates unrelated to graduated licensing laws. Results: Compared with licensing laws rated poor, laws rated good were associated with 30 percent lower fatal crash rates among 15- to 17-year-olds. Laws rated fair yielded fatal crash rates 11 percent lower. The longer the permit age was delayed, or the longer the licensing age was delayed, the lower the estimated fatal crash rates among 15- to 17-year-olds. Stronger nighttime restrictions were associated with larger reductions, and reductions were larger for laws limiting teenage passengers to zero or one than laws allowing two or more teenage passengers or laws without passenger restrictions. After the effects of any related delay in licensure were accounted for, an increase in the minimum learners permit holding period showed no association with fatal crash rates. An increase in required practice driving hours did not appear to have an independent association with fatal crash rates. Conclusions: Graduated licensing laws that include strong nighttime and passenger restrictions and laws that delay the learners permit age and licensing age are associated with lower teenage fatal crash rates. States that adopt such laws can expect to achieve substantial reductions in crash deaths.

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.

Volvo and Infiniti Drivers’ Experiences With Select Crash Avoidance Technologies

Objectives: Vehicle-based crash avoidance systems can potentially reduce crashes, but success depends on driver acceptance and understanding. This study gauged driver use, experience, and acceptance among early adopters of select technologies. Methods: Telephone interviews were conducted in early 2009 with 380 owners of Volvo vehicles equipped with forward collision warning with autobrake, lane departure warning, side-view assist, and/or active bi-xenon headlights and 485 owners of Infiniti vehicles with lane departure warning/prevention. Results: Most owners kept systems turned on most of the time, especially forward collision warning with autobrake and side-view assist. The exception was lane departure prevention; many owners were unaware they had it, and the system must be activated each time the vehicle is started. Most owners reported being safer with the technologies and would want them again on their next vehicles. Perceived false or unnecessary warnings were fairly common, particularly with side-view assist. Some systems were annoying, especially lane departure warning. Many owners reported safer driving behaviors such as greater use of turn signals (lane departure warning), increased following distance (forward collision warning), and checking side mirrors more frequently (side-view assist), but some reported driving faster at night (active headlights). Conclusions: Despite some unnecessary or annoying warnings, most Volvo and Infiniti owners use crash avoidance systems most of the time. Among early adopters, the first requirement of effective warning systems (that owners use the technology) seems largely met. Systems requiring activation by drivers for each trip are used less often. Owner experience with the latest technologies from other automobile manufacturers should be studied, as well as for vehicles on which technologies are standard (versus optional) equipment. The effectiveness of technologies in preventing and mitigating crashes and injuries, and user acceptance of interfaces, should be examined as more vehicles with advanced technologies penetrate the fleet.

National reported patterns of driver cell phone use in the United States.

Objectives: To obtain detailed information on patterns of driver cell phone use, including how often drivers talk and text, the extent to which they use hands-free devices, and knowledge of and reaction to state cell phone laws. Methods: Telephone surveys were conducted with 1219 drivers in the 48 contiguous U.S. states and the District of Columbia, using random samples of landline and cell phone numbers. Results: Forty percent of drivers reported talking on phones at least a few times per week. The percentages were highest for males (49%) and drivers ages 25–29 (66%). The percentage of drivers who reported never talking on phones was higher in states with all-driver bans on handheld phone use (44%) than in states without a ban applying to all drivers (30%). The percentage of drivers who talk on phones and always talk hands-free was higher in states with all-driver handheld phone bans (22%) than where such bans are not in effect (13%). Thirteen percent of drivers reported some texting while driving, and this percentage was highest among drivers ages 18–24 (43%). Twelve percent of drivers in states with all-driver texting bans reported texting while driving, compared with 14 percent in states with no texting ban. Among drivers ages 18–24, the percentages were 45 and 48 percent, respectively. Conclusions: Most drivers reported talking on phones while driving, even though earlier surveys have found that most people think this behavior should be banned. Fewer drivers overall reported texting, but the frequency of texting was higher among young drivers. Laws banning handheld phone use seem to discourage some drivers from talking on any type of phone and motivate some drivers to talk hands-free. Laws banning texting while driving have little effect on the reported frequency of texting while driving in any age group.

Cell phone use while driving and attributable crash risk.

Objectives: Prior research has estimated that crash risk is 4 times higher when talking on a cell phone versus not talking. The objectives of this study were to estimate the extent to which drivers talk on cell phones while driving and to compute the implied annual number of crashes that could have been avoided if driver cell phone use were restricted. Methods: A national survey of approximately 1200 U.S. drivers was conducted. Respondents were asked to approximate the amount of time spent driving during a given day, number of cell phone calls made or received, and amount of driving time spent talking on a cell phone. Population attributable risk (PAR) was computed for each combination of driver gender, driver age, day of week, and time of day. These were multiplied by the corresponding crash counts to estimate the number of crashes that could have been avoided. Results: On average, drivers were talking on cell phones approximately 7 percent of the time while driving. Rates were higher on weekdays (8%), in the afternoon and evening (8%), and for drivers younger than 30 (16%). Based on these use rates, restricting cell phones while driving could have prevented an estimated 22 percent (i.e., 1.3 million) of the crashes in 2008. Conclusions: Although increased rates of cell phone use while driving should be leading to increased crash rates, crash rates have been declining. Reasons for this paradox are unclear. One possibility is that the increase in cell phone use and crash risk due to cell phone use have been overestimated. Another possibility is that cell phone use has supplanted other driving distractions that were similarly hazardous.

Changes in Self-Regulatory Driving Among Older Drivers Over Time

Objectives: The primary goal of the study was to identify to what extent older people modify their driving, what influences them to do so, and how self-regulatory behavior changes over time in relation to changes in perceived impairments and lifestyle characteristics. Methods: Participants 65 and older (n = 2650) were recruited while renewing their drivers licenses in Connecticut, Kentucky, and Rhode Island and were interviewed by telephone about current driving patterns, recent changes in driving, functional abilities related to driving (i.e., vision, memory, physical mobility, diagnosed medical conditions), crash involvements, and lifestyle characteristics. Participants were called annually to participate in follow-up telephone interviews; 2057 completed a second interview, 1698 completed 3 interviews, and 1437 completed all 4 interviews. Stepwise regression analyses examined how changes in impairments and life events (i.e., retiring, becoming widowed or divorced) related to changes in the number of miles driven during a typical week and in the number of driving situations avoided. Results: Based on information provided in the initial survey, participants who completed all 4 surveys were slightly younger, more likely to be married, slightly less impaired in terms of physical mobility and medical conditions, and drove more weekly miles and avoided fewer driving situations compared with those who dropped out. Participants who completed all 4 interviews reported driving an average of 94 miles per week in year 1 compared with 78 miles in year 4. Reported impairments generally were low to moderate and changed little. Analyses comparing years 1 and 4 indicated that drivers drove 35 fewer miles per week if they retired or lost their job and 61 fewer miles if they moved from a retirement home to a private home or assisted living. They drove 25 more miles per week on average if they became widowed or divorced. Small increases in the number of driving situations avoided were associated with increasing impairments in memory and mobility. Conclusions: Lifestyle changes such as becoming widowed or divorced or retiring were associated with changes in mileages. Older drivers with worsening memory and physical mobility regulated their driving to some extent by avoiding more driving situations, confirming the hypothesis that some older drivers do take steps to compensate for increases in some perceived impairments. However, during the 3-year study period, reported changes were not large, perhaps because older drivers with larger changes were among those who dropped out (46% of those who took the first survey).

TRB Workshop 2007: Licensing authorities' options for managing older driver safety--practical advice from the researchers

JIM LANGFORD,1 KELI BRAITMAN,2 JUDE CHARLTON,3 JOHN EBERHARD,4 DESMOND O’NEILL,5 LOREN STAPLIN,6 and JANE STUTTS7 1Monash University Accident Research Centre (Convenor), Victoria, Australia 2Insurance Institute for Highway Safety, Arlington, Virginia, USA 3Monash University Accident Research Centre, Victoria, Australia 4Seniar Consultant, Howard County Commission on Aging, Colombia, Maryland, USA 5Trinity College, Dublin, Republic of Ireland 6TransAnalytics, LLC, Kulpsville, Pennsylvania, USA 7University of North Carolina Highway Safety Research Center, Chapel Hill, North Carolina, USA

Views of Parents of Teenagers About Licensing Policies: A National Survey

Objective: During the past two decades, many changes in licensing policies have been made in U.S. states, and more are being discussed. The views of parents of teenagers can inform debates about what licensing provisions should be considered and how well they will be received. The objective was to obtain the views of a nationally representative sample of parents of teenagers on a wide range of licensing practices. Methods: Parents were interviewed via the internet in early 2010. Participants were 1226 parents of 15- to 18-year-olds drawn from a nationally representative panel of U.S. households recruited using probability-based sampling. The panel included cell phone–only households, and Internet access was provided to those without it. Weighting procedures were applied to ensure that participants reflect the national population. Results: Parents generally favored licensing policies that are as strong as or stronger than exist in any U.S. jurisdiction, including higher permit and licensing ages, long learner periods with high practice hour requirements, plus strong and long-lasting night and passenger restrictions. The majority of parents approved of tougher driving tests, including a test to graduate to full license status (75%), enhanced penalties for traffic violations (94%) and violations of graduated licensing restrictions (78%), cell phone and texting bans (96–98%), and, to a somewhat lesser extent, license status identifiers (decals) on vehicles (65%) and the application of graduated licensing rules to novice drivers 18 and older (61%). Parents in the Northeast were significantly more supportive of older learners permit and restricted driving ages than parents in other regions, and parents in the West were more supportive of strong passenger restrictions. Conclusions: Results suggest that many parents will support comprehensive licensing policies. Many of these policies are known to reduce teenage crash involvement. For others, research evidence of their effects is lacking and needs to be established.

Restricted licensing among older drivers in Iowa

OBJECTIVES To determine whether Iowas license restriction program identifies older drivers who appear to be at greater crash risk and to assess compliance with license restrictions. METHODS A total of 522 drivers 70 and older who were attempting to renew their drivers licenses at licensing offices in Iowa participated in two telephone surveys: one shortly after renewal to discuss driving before renewal and another 6months later to assess any changes. Surveys assessed driving behavior, crashes, and violations as well as self-reported visual impairments, prescription medications, and physical mobility limitations. RESULTS Of the 522 drivers, 232 renewed their licenses without having to take a road test (Group 1), and 290 were required to take a road test; of the drivers taking a road test, 191 renewed without restrictions (Group 2), 93 received restrictions (Group 3), and 6 had their licenses suspended (Group 4). The small number of drivers with suspensions precluded including this group in analyses. There were clear distinctions among drivers in the first three groups at the initial survey. Driver age increased across Groups 1-3, as did some visual impairments, number of prescription medications, and physical mobility limitations. Many drivers who received restrictions (Group 3) already were driving fewer miles than drivers in Groups 1-2, and were driving less often at night and on high-speed roads. Following license renewal, reported average weekly mileage decreased more among drivers with license restrictions (Group 3) (36%) than among drivers without restrictions (Groups 1-2) (4% each). For all license restriction types (headlight, geographic area, or speed), decreases in the likelihood of driving during these restricted conditions were greater for drivers with the relevant restrictions than without. Most drivers complied with restrictions. CONCLUSIONS Iowas license restriction program identifies drivers with more self-reported visual impairments, prescription medications, and physical mobility limitations. Driving exposure was reduced among drivers who received restrictions, though it appears in some cases the restrictions reinforced decisions already made by drivers. IMPACT ON INDUSTRY License restrictions may be an effective alternative to premature driving cessation and provide some drivers additional time on the road and hence continued mobility and independence. However, overall safety benefits of license restrictions are yet unknown.