Validation of an electronic device for measuring driving exposure

OBJECTIVE: This study sought to evaluate an on-board diagnostic system (CarChip) for collecting driving exposure data in older drivers. METHODS: Drivers (N = 20) aged 60 to 86 years from Winnipeg and surrounding communities participated. Information on driving exposure was obtained via the CarChip and global positioning system (GPS) technology on a driving course, and obtained via the CarChip and surveys over a week of driving. Velocities and distances were measured over the road course to validate the accuracy of the CarChip compared to GPS for those parameters. RESULTS: The results show that the CarChip does provide valid distance measurements and slightly lower maximum velocities than GPS measures. From the results obtained in this study, it was determined that retrospective self-reports of weekly driving distances are inaccurate. CONCLUSIONS: Therefore, an on-board diagnostic system (OBDII) electronic device like the CarChip can provide valid and detailed information about driving exposure that would be useful for studies of crash rates or driving behavior.     

Characteristics and risks of drivers with low annual distance driven

OBJECTIVES: It has been noted by several authors that risk (defined only in terms of total expected numbers of crash involvements per total distance driven) paints a misleading picture of crash liability, particularly for the young and the old, as their high risk is associated with risky driving patterns typical of people who drive low annual kms. This article sets out to analyze these driving patterns of low-km drivers and to evaluate the risk of these patterns. As licensing programs tend to focus on young and old drivers, who tend to drive lower annual distances, income and employment data are also analyzed for low-km drivers. This is to provide a better picture for policy makers of the sort of people and the sorts of transportation requirements that their policies may affect. METHODS: Crash data and travel data were disaggregated by driver characteristics and by driving conditions (road type, day and night, weekend and weekday) and combined to form estimates of risk for typical driving patterns of driver groups. Characteristics of driving patterns and of the drivers themselves were derived for groups defined by age and by the amount of annual driving undertaken. RESULTS: Older drivers who drive less tend to have higher risk per km mainly due to their predominantly urban trips. Nevertheless, because older drivers on average manage to reduce their risk per distance driven by choosing driving patterns that are safer than the driving patterns of other age groups, the risk of older drivers as a group is not overestimated. CONCLUSION: Despite being quite different from one another, the low- and high-km driving patterns of younger drivers were found to impose identical risks.     

Are older drivers’ driving patterns during an on-road driving task representative of their real-world driving patterns?

Abstract

Objective: The current study investigated whether older drivers’ driving patterns during a customized on-road driving task were representative of their real-world driving patterns.

Methods: Two hundred and eight participants (male: 68.80%; mean age?=?81.52 years, SD?=?3.37 years, range?=?76.00–96.00 years) completed a customized on-road driving task that commenced from their home and was conducted in their own vehicle. Participants’ real-world driving patterns for the preceding 4-month period were also collected via an in-car recording device (ICRD) that was installed in each participant’s vehicle.

Results: During the 4-month period prior to completing the on-road driving task, participants’ median real-world driving trip distance was 2.66?km (interquartile range [IQR]?=?1.14–5.79?km) and their median on-road driving task trip distance was 4.41?km (IQR?=?2.83–6.35?km). Most participants’ on-road driving task trip distances were classified as representative of their real-world driving trip distances (95.2%, n?=?198).

Conclusions: These findings suggest that most older drivers were able to devise a driving route that was representative of their real-world driving trip distance. Future research will examine whether additional aspects of the on-road driving task (e.g., average speed, proportion of trips in different speed zones) are representative of participants’ real-world driving patterns.     

Driving safety improves after individualized training: An RCT involving older drivers in an urban area

Objective: This study aimed to reproduce the results of a previous investigation on the safety benefits of individualized training for older drivers. We modified our method to address validity and generalizability issues.

Methods: Older drivers were randomly assigned to one of the 3 arms: (1) education alone, (2) education?+?on road training, and (3) education?+?on road?+?simulator training. Older drivers were recruited from a larger urban community. At the pre- and posttests (separated by 4 to 8 weeks) participants followed driving directions using a Global Positioning System (GPS) navigation system.

Results: Our findings support the positive influence of individualized on-road training for urban-dwelling older drivers. Overall, driving safety improved among drivers who received on-road training over those who were only exposed to an education session, F(1, 40) = 11.66, P = .001 (26% reduction in total unsafe driving actions [UDAs]). Statistically significant improvements were observed on observation UDAs (e.g., scanning at intersections, etc.), compliance UDAs (e.g., incomplete stop), and procedural UDAs (e.g., position in lane).

Conclusion: This study adds to the growing evidence base in support of individualized older driver training to optimize older drivers’ safety and promote continued safe driving.     

The impact of intersection design on simulated driving performance of young and senior adults

PURPOSE: The Federal Highway Administration (FHWA) proposed guidelines for highway design to increase the safe driving ability of older drivers; however, little empirical evidence exists to support the effectiveness of these guidelines. The purpose of this study was to investigate the effects of implementing these guidelines (in 4 pairs of intersections) on safe driving performance of older and younger drivers using a high-fidelity driving simulator. DESIGN AND METHODS: We replicated four intersection pairs (improved versus unimproved) in a high-fidelity, virtual reality driving simulator. Simulator scenarios were created from actual road locations, replicating road geometrics and traffic control devices. The simulator's controls were integrated with an actual vehicle to make the driving experience as realistic as possible. Kinematic measures were obtained from the simulator in conjunction with driving errors recorded by trained driving evaluators sitting in the cab of the car. Thirty-nine subjects, 19 younger and 20 older adults, participated in the study. RESULTS: For the kinematic data we found greater lateral control, as indicated by significantly smaller maximum yaw during the turn phase, at all of the improved intersections when compared to the unimproved intersections. We found some significant age differences, but mostly in only one of the intersection-pairs. For the behavioral data, there were significant differences in driving errors between improved and unimproved intersections in two intersection-pairs; however, there were no significant differences in driving errors between the older and younger drivers. IMPLICATIONS: The findings suggest that both young and older drivers may benefit from roadways with safety features recommended by the FHWA guidelines as indicated by the increased lateral control of the vehicle when negotiating these intersections. These findings generate critical information for those involved in the design of roadway systems.     

Driving exposure by driver age in Michigan

Background

This study compared driving exposure between two high-crash-risk groups (16–17 and 18-24-year-olds), with a low-crash-risk group (35-64-year-olds). In addition, patterns of association between driving exposure measures and demographic and driving behavior variables were examined.

Methods

Respondent's total miles, minutes, and trips driven were calculated within a 48-hour period, using state-wide survey data collected in 2004 and 2005.

Results

The youngest drivers drove fewer miles and minutes, but a comparable number of trips as the two older groups. Employment and high vehicle access were associated with greater driving exposure for 16-17-year-olds and 18-24-year-olds. Employment, high household income, large household size, and low vehicle access were associated with greater driving exposure for 35-64-year-olds. More driving was done alone than with passengers present and during the day than at night across all ages. There was a positive association between two driving exposure measures (miles and minutes driven) and demographic and driving behavior variables, which did not extend to trips driven.

Discussion

Driving exposure is directly related to stage of life. The entire sample of 16-17-year-old respondents were in high school, which directly influenced their driving times, destinations, and purpose. Those aged 18–24 years displayed driving behavior patterns that were closer to the older drivers, while retaining some differences. The oldest drivers were likely to be shouldering the greatest household responsibilities, and their greater driving exposure may reflect this reality.

Impact on industry

These findings provide new information about driving exposure for two high-risk and one low-risk group of drivers. They also raise concern over potential workplace safety issues related to teens’ higher driving exposure, and concomitant crash risk, related to being employed. Future research should examine this issue more carefully so that evidence based recommendations can be made to enhance the safety of teens who are employed, especially those who are employed as drivers.     

Effectiveness of mandatory license testing for older drivers in reducing crash risk among urban older Australian drivers

Most licensing jurisdictions in Australia maintain mandatory assessment programs targeting older drivers, whereby a driver reaching a specified age is required to prove his or her fitness to drive through medical assessment and/or on-road testing. Previous studies both in Australia and elsewhere have consistently failed to demonstrate that age-based mandatory assessment results in reduced crash involvement for older drivers. However studies that have based their results upon either per-population or per-driver crash rates fail to take into account possible differences in driving activity. Because some older people maintain their driving licenses but rarely if ever drive, the proportion of inactive license-holders might be higher in jurisdictions without mandatory assessment relative to jurisdictions with periodic license assessment, where inactive drivers may more readily either surrender or lose their licenses. The failure to control for possible differences in driving activity across jurisdictions may be disguising possible safety benefits associated with mandatory assessment. The current study compared the crash rates of drivers in Melbourne, Australia, where there is no mandatory assessment and Sydney, Australia, where there is regular mandatory assessment from 80 years of age onward. The crash rate comparisons were based on four exposure measures: per population, per licensed driver, per distance driven, and per time spent driving. Poisson regression analysis incorporating an offset to control for inter-jurisdictional road safety differences indicated that there was no difference in crash risk for older drivers based on population. However drivers aged 80 years and older in the Sydney region had statistically higher rates of casualty crash involvement than their Melbourne counterparts on a per license issued basis (RR: 1.15, 1.02-1.29, p=0.02) and time spent driving basis (RR: 1.19, 1.06-1.34, p=0.03). A similar trend was apparent based on distance travelled but was of borderline statistical significance (RR: 1.11, 0.99-1.25, p=0.07). Collectively, it can be inferred from these findings that mandatory license re-testing schemes of the type evaluated have no demonstrable road safety benefits overall. Further research to resolve this on-going policy debate is discussed and recommended.     

Older driver crash rates in relation to type and quantity of travel

It is a well-established phenomenon that, notwithstanding their overall good crash record, older drivers have a higher than average rate of involvement in injury crashes when the rate is calculated by dividing crash numbers by distance driven. It has been hypothesised that at least some of this higher crash rate is an artefact of the different nature of driving undertaken by many older drivers. For example, driving in congested urban environments provides more opportunities for collisions than driving the same distance on a motorway. However, there have been few opportunities to investigate this theory, as relevant data are difficult to acquire. High-quality data from the New Zealand Travel Survey (1997/1998) were combined with crash data to enable a statistical model to estimate the risk of driver groups under various driving conditions characterised by the type of road used, time of day, day of week, and season of year. Despite elevated crash risks per distance driven compared with middle-aged drivers for most road types, older drivers were as safe as any other age group when driving on motorways. Accounting for the fragility of older drivers and their passengers in the risk estimates for other road types, older drivers appeared to have daytime risks comparable to 25-year-olds and night-time risks as low as any other age group. The driving patterns of older drivers (in terms of when and where they drive) were estimated to minimize their risks in comparison with the driving patterns of other age groups. These results are of interest to both policy makers and transportation planners working against the background of inevitable increases in the number of older drivers as the population ages.     

Classifying and predicting risky driving among novice drivers: A group-based trajectory approach

Introduction: Classifying risky driving among new teenage drivers is important for efficiently targeting driving interventions. We thoroughly investigated whether novice drivers can be clustered by their driving outcome profiles over time. Methods: A sample of 51 newly licensed teen drivers was recruited and followed over a period of 20 weeks. An in-vehicle video recording system was used to gather data on dangerous driving events referred to as DDEs (elevated g-force, near-crash, and crash events), risky driving behaviors referred to as RDBs (e.g., running stop signs, cell phone use while driving), and miles traveled. The DDE and RDB weekly rates rate were determined by dividing the number of DDEs and RDBs in a week by the number of miles traveled in that week, respectively. Group-based trajectory modeling was used to map the clustering of DDE rate and RDB rate patterns over time and their associated covariates. Results: Two distinct DDE rate patterns were found. The first group (69.1% of the study population) had a lower DDE rate which was consistent over time. The second had a higher DDE rate pattern (30.9%) and characterized by a rising trend in DDE rate followed by a steady decrease (inverted U-shaped pattern). Two RDB rate patterns were also identified: a lower RDB rate pattern (83.4% of the study population) and a higher RDB rate pattern (16.6%). RDB and DDE rate patterns were positively related, and therefore, co-occurred. The results also showed that males were more likely than females to be in the higher DDE and RDB rate patterns. Conclusion: The groups identified by trajectory models may be useful for targeting driving interventions to teens that would mostly benefit as the different trajectories may represent different crash risk levels. Practical applications: Parents using feedback devices to monitor the driving performance of their teens can use the initial weeks of independent driving to classify their teens as low or high-risk drivers. Teens making a very few DDEs during their early weeks of independent driving are likely to remain in the lower risk group over time and can be spared from monitoring and interventions. However, teens making many DDEs during their initial weeks of unsupervised driving are likely to continue to make even more DDEs and would require careful monitoring and targeted interventions.     

Teaching older drivers to navigate GPS technology

Background and objectives: New technologies are being implemented in motor vehicles. One key technology is the electronic navigation system (ENS) that assists the driver in wayfinding, or actually guides the vehicle in higher level automation vehicles. It is unclear how older adults interact with ENSs and the best approach to train older adults to use the devices. The objectives of this study were to explore how older drivers interacted with an ENS while driving on live roadways and how various training approaches impacted older drivers’ ability to accurately enter destinations into the ENS. Research design and methods: In Experiment 1, 80 older drivers navigated unfamiliar routes using an ENS or paper directions and completed a series of ENS destination entry tasks. In Experiment 2, 60 older drivers completed one of three training conditions (ENS video only, ENS video with hands-on training, placebo) to examine the impacts of training on destination entry performance. Results and discussion: Driving performance was aided by the use of the ENS, but many older drivers had difficulty entering destinations into the device (Experiment 1). The combined video with hands-on ENS training resulted in the best overall destination entry performance (Experiment 2). Practical applications: The results suggest older drivers may experience problems entering destinations into ENSs, but training can improve performance. These performance issues may be especially important as more vehicle features require interaction with computer systems to select destinations or other automation related features. Further research is needed to determine how to prepare the next generation of older drivers who will interact with technologies aimed at increasing mobility.     

Deconstructing a gender difference: driving cessation and personal driving history of older women

PROBLEM: The purpose of this study is to understand the reasons behind older women's driving cessation by comparing the driving histories of Finnish women who either gave up or renewed their drivers license at the age of 70. METHOD: A mail survey was sent to all Finnish women born in 1927 who gave up their license in 1997 (N=1,476) and to a corresponding random sample of women who renewed their license (N=1,494). The total response rate was 42.1%. RESULTS: The length and level of activity of personal driving history were strongly associated with driving cessation and continuation. Ex-drivers tended to have an inactive driving career behind them, whereas drivers had a more active personal driving history. In addition, those women with an active, "male-like" driving history who had decided to stop driving gave reasons for driving cessation that were similar to what is known about older men's reasons to give up driving. The results suggest that the decision to stop driving is related to driving habits rather than gender.     

Distraction in older drivers - A face-to-face interview study

The prevalence of older drivers’ engagement in distracting activities while driving is largely unexplored. Face-to-face interviews were conducted in the city of Braunschweig, Germany, comparing a sample of older drivers (n = 205) to a group of middle-aged drivers (n = 209). The drivers were interviewed on their engagement in distracting activities during the last half an hour of their driving trip, including the frequency and duration of these activities, their perception of the risk associated with these distracting activities and the role of these activities in at-fault crashes. Middle-aged drivers were significantly more likely to engage in certain distracting activities than older drivers. With regard to the duration of interactions with the passengers older drivers were significantly more talkative than middle-aged drivers. Middle-aged drivers rated most of the distracting activities as significantly less dangerous than older drivers. Distraction-related crashes are not a special problem of older drivers but seem to be very comparable to the middle-aged drivers. It is concluded that older drivers’ reluctance to engage in distracting tasks while driving is either a process of self-regulation or their age-related prudence. The study is the first to gather knowledge about distraction in German older drivers. Although older drivers are not currently overrepresented in distraction-related crashes, it is important to note that future cohorts of older drivers might differ in the way they engage with vehicles and technologies, which in turn may influence their driving patterns and willingness to engage in potentially distracting activities.     

Young drivers' responses to anti-speeding advertisements: Comparison of self-report and objective measures of persuasive processing and outcomes

Objective: Self-report measures are typically used to assess the effectiveness of road safety advertisements. However, psychophysiological measures of persuasive processing (i.e., skin conductance response [SCR]) and objective driving measures of persuasive outcomes (i.e., in-vehicle Global Positioning System [GPS] devices) may provide further insights into the effectiveness of these advertisements. This study aimed to explore the persuasive processing and outcomes of 2 anti-speeding advertisements by incorporating both self-report and objective measures of speeding behavior. In addition, this study aimed to compare the findings derived from these different measurement approaches.

Methods: Young drivers (N = 20, M age = 21.01 years) viewed either a positive or negative emotion–based anti-speeding television advertisement. While viewing the advertisement, SCR activity was measured to assess ad-evoked arousal responses. The RoadScout GPS device was then installed in participants' vehicles for 1 week to measure on-road speed-related driving behavior. Self-report measures assessed persuasive processing (emotional and arousal responses) and actual driving behavior.

Results: There was general correspondence between the self-report measures of arousal and the SCR and between the self-report measure of actual driving behavior and the objective driving data (as assessed via the GPS devices).

Conclusions: This study provides insights into how psychophysiological and GPS devices could be used as objective measures in conjunction with self-report measures to further understand the persuasive processes and outcomes of emotion-based anti-speeding advertisements.     

Taxi driver speeding: Who,when, where and how? A comparative study between Shanghai and New York City

Objective: The 3 objectives of this study are to (1) identify the driving style characteristics of taxi drivers in Shanghai and New York City (NYC) using taxi Global Positioning System (GPS) data and make a comparative analysis; (2) explore the influence of different driving style characteristics on the frequency of speeding (who and how?) and (3) explore the influence of driving style characteristics, road attributes, and environmental factors on the speeding rate (when, where, and how?)

Methods: This study proposes a driver–road–environment identification (DREI) method to investigate the determinant factors of taxi speeding violations. Driving style characteristics, together with road and environment variables, were obtained based on the GPS data and auxiliary spatiotemporal data in Shanghai and NYC.

Results: The daily working hours of taxi drivers in Shanghai (18.6 h) was far more than in NYC (8.5 h). The average occupancy speed of taxi drivers in Shanghai (21.3 km/h) was similar to that of NYC (20.3 km/h). Speeders in both cities had shorter working hours and longer daily driving distance than other taxi drivers, though their daily income was similar. Speeding drivers routinely took long-distance trips (>10 km) and preferred relatively faster routes. Length of segments (1.0–1.5 km) and good traffic condition were associated with high speeding rates, whereas central business district area and secondary road were associated with low speeding rates. Moreover, many speeding violations were identified between 4:00 a.m. and 7:00 a.m. in both Shanghai and NYC and the worst period was between 5:00 a.m. and 6:00 a.m. in both cities.

Conclusions: Characteristics of drivers, road attributes, and environment variables should be considered together when studying driver speeding behavior. Findings of this study may assist in stipulating relevant laws and regulations such as stricter offense monitoring in the early morning, long segment supervision, shift rule regulation, and working hour restriction to mitigate the risk of potential crashes.     

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.     

Adaptive response criteria in road hazard detection among older drivers

Objectives: The majority of existing investigations on attention, aging, and driving have focused on the negative impacts of age-related declines in attention on hazard detection and driver performance. However, driving skills and behavioral compensation may accommodate for the negative effects that age-related attentional decline places on driving performance. In this study, we examined an important question that had been largely neglected in the literature linking attention, aging, and driving: can top-down factors such as behavioral compensation, specifically adaptive response criteria, accommodate the negative impacts from age-related attention declines on hazard detection during driving?

Methods: In the experiment, we used the Drive Aware Task, a task combining the driving context with well-controlled laboratory procedures measuring attention. We compared younger (n = 16, age 21–30) and older (n = 21, age 65–79) drivers on their attentional processing of hazards in driving scenes, indexed by percentage of correct responses and reaction time of hazard detection, as well as sensitivity and response criteria using signal detection analysis.

Results: Older drivers, in general, were less accurate and slower on the task than younger drivers. However, results from this experiment revealed that older, but not younger, drivers adapted their response criteria when the traffic condition changed in the driving scenes. When there was more traffic in the driving scene, older drivers became more liberal in their responses, meaning that they were more likely to report that a driving hazard was detected.

Conclusions: Older drivers adopt compensatory strategies for hazard detection during driving. Our findings showed that, in the driving context, even at an older age our attentional functions are still adaptive according to environmental conditions. This leads to considerations on potential training methods to promote adaptive strategies that may help older drivers maintain performance in road hazard detection.     

A cost-benefit analysis of risk-reduction strategies targeted at older drivers

OBJECTIVE: The risk of motor-vehicle collisions increases as driving-related functional abilities decline. These declines can accompany normal or pathological aging and can be identified through driving-related functional screening exams upon license renewal. The objective of this cost-benefit analysis was to determine the utility of four functional screening procedures used to identify drivers at risk for motor-vehicle collisions, as well as an intervention designed to maintain or improve functional abilities. Additionally, this study sought to determine the expected cost per driver if an intervention was designed to target only those drivers who failed the functional ability-based driving screen, versus the expected cost per driver if the intervention was distributed en masse to all drivers 75 years and older. Improving functional abilities in older adults has potential far-reaching health and financial impacts which are broader than their impact of maintaining mobility. METHODS: A decision tree was constructed to evaluate the expected costs and benefits of (a) screening all drivers and intervening when indicated (several screening batteries of varying length were considered), (b) no screening, but intervening with all drivers of older age, or (c) neither screening nor intervening (i.e., re-licensing per usual). Test characteristics and risk probabilities were based on a cohort of drivers aged 75 and older from a previous study (Ball et al., 2006). Relevant sensitivity analyses were conducted. RESULTS: Providing all drivers with the speed-of-processing intervention is the most cost-beneficial option (expected cost per driver = $493.30), even if the cost of the intervention doubles. Sensitivity analysis indicated the effectiveness of the intervention could drop from 86% to 25% and the preventative approach of intervening with all drivers remains the most cost-beneficial strategy. The least cost-beneficial option is almost always re-licensing per usual (expected cost per driver = $1,562.84). CONCLUSION: Screening drivers upon license renewal is not currently beneficial because the available technology cannot consistently identify drivers at risk for a collision. However, the speed-of-processing intervention has demonstrated efficacy in improving driving competence (Roenker et al., 2003) and is a non-invasive, moderate-cost intervention that has the potential to protect the safety and mobility, as well as the financial interests, of older drivers and the community at large.     

Using a driving simulator to identify older drivers at inflated risk of motor vehicle crashes

PROBLEM: To develop appropriate assessment criteria to measure the performance of older drivers using an interactive PC-based driving simulator, and to determine which measures were associated with the occurrence of motor-vehicle crash. METHOD: One hundred and twenty-nine older drivers residing in a metropolitan city volunteered to participate in this retrospective cohort study. Using the driving simulator, appropriate driving tasks were devised to test the older drivers, whose performances were assessed by 10 reliable assessment criteria. Logistic regression analysis was then undertaken to determine those criteria that influence the self-reported crash outcome. RESULTS: As expected, driving skill of older drivers was found to decline with age. Over 60% of the sample participants reported having at least one motor-vehicle crash during the past year. Adjusting for age in a logistic regression analysis, the cognitive abilities associated with the crash occurrence were working memory, decision making under pressure of time, and confidence in driving at high speed. SUMMARY: The findings of this retrospective study indicated those individuals at inflated risk of vehicle crashes could be identified using the PC-based interactive driving simulator. Prospective studies need to be undertaken to determine whether the driving simulator can predict future crash events. IMPACT ON INDUSTRY: This study demonstrated an economical driving simulator approach to screen out problematic or unsafe older drivers before a more detailed but expensive road test is considered.     

Driving circumstances and accidents among novice drivers

OBJECTIVE: The study evaluated the accident risk of certain driving circumstances and driving motives among novice drivers. METHODS: Self-reported exposure and accidents according to driving circumstances and driving motives were compared between young (n = 6,847) and middle-aged (n = 942) male and female novice drivers. For young drivers, self-reported accidents were further compared to fatal accidents (n = 645) in terms of the driving conditions in which they occurred. The survey was conducted in 2002 and the questions regarding the quantity and quality of driving exposure and accidents covered the first four years of the novice drivers' driving career after licensing. Data on fatal accidents related to the period of 1990 to 2000. RESULTS: Leisure-time driving, driving just for fun, and driving with passengers and during evenings and at night was more typical for young drivers than for middle-aged drivers. For middle-aged drivers, the most typical driving was driving to or from work. Driving on errands was more typical for females than males. Nighttime driving was overrepresented in young drivers' self-reported and fatal accidents, compared to the share of young drivers' driving at night. Slippery road conditions were over-represented in young male drivers' self-reported accidents, but not in their fatal accidents, whereas for young females slippery road conditions seemed to increase the propensity of fatal accidents. CONCLUSIONS: The study concluded that some driving conditions increase the risk of certain types of accidents among certain driver groups, but not among all drivers. For example, slippery road conditions were overrepresented in young male drivers' minor (self-reported) accidents, but not in their fatal accidents. For young female drivers slippery road conditions seem to increase the propensity of fatal accidents. Driving circumstances are different in minor (self-reported) and fatal accidents. When drawing conclusions regarding accident risk, it is important to determine the seriousness of the accidents which take place.     

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.