Teen drivers' awareness of vehicle instrumentation in naturalistic research.

INTRODUCTION: Naturalistic driving methods require the installation of instruments and cameras in vehicles to record driving behavior. A critical, yet unexamined issue in naturalistic driving research is the extent to which the vehicle instruments and cameras used for naturalistic methods change human behavior. We sought to describe the degree to which teenage participants' self-reported awareness of vehicle instrumentation changes over time, and whether that awareness was associated with driving behaviors. METHOD: Forty-two newly-licensed teenage drivers participated in an 18-month naturalistic driving study. Data on driving behaviors including crash/near-crashes and elevated gravitational force (g-force) events rates were collected over the study period. At the end of the study, participants were asked to rate the extent to which they were aware of instruments in the vehicle at four time points. They were also asked to describe their own and their passengers' perceptions of the instrumentation in the vehicle during an in-depth interview. The number of critical event button presses was used as a secondary measure of camera awareness. The association between self-reported awareness of the instrumentation and objectively measured driving behaviors was tested using correlations and linear mixed models. RESULTS: Most participants' reported that their awareness of vehicle instrumentation declined across the duration of the 18-month study. Their awareness increased in response to their passengers' concerns about the cameras or if they were involved in a crash. The number of the critical event button presses was initially high and declined rapidly. There was no correlation between driver's awareness of instrumentation and their crash and near-crash rate or elevated g-force events rate. CONCLUSION: Awareness was not associated with crash and near-crash rates or elevated g-force event rates, consistent with having no effect on this measure of driving performance. PRACTICAL APPLICATIONS: Naturalistic driving studies are likely to yield valid measurements of driving behavior.

Naturalistic assessment of the learner license period.

The purpose of this study was to describe the characteristics and progression of practice driving during the learner license period in a sample of teenagers. During the first and last 10h of practice driving, we examined (1) the amount, variety and complexity of conditions of practice; (2) the nature of parental instruction; and (3) errors that teens made while driving. Data were collected from 90 teens and 131 parents living in Virginia, USA, using in-vehicle cameras, audio recorders, GPS and trip recorders. Based on data collected from the instrumented vehicles, teens practiced for 46.6h on average, slightly higher than the GDL requirement for their jurisdiction, though half did not complete the required 45h of practice and only 17% completed the required 15h of night time driving. Exposure to diverse roadways increased over the practice driving period, which averaged 10.6 months. Most driving instruction occurred in reaction to specific driving situations, such as navigating and identifying hazards, and could be characterized as co-driving. Higher order instruction, which relates to the tactics or strategies for safe driving, was less frequent, but remained stable through the practice driving period. Instruction of all forms was more likely following an elevated gravitational force (g-force) event. Errors decreased over time, suggesting improvements in manual and judgment skills, but engagement in potentially distracting secondary tasks increased (when an adult was in the vehicle). A small percentage of trips occurred with no passenger in the front seat, and the g-force rate during these trips was almost 5 times higher than trips with an adult front-seat passenger. Taken collectively, these findings indicate (1) most teens got at least the required amount of supervised practice, but some did not; (2) instruction was mainly reactive and included some higher order instruction; (3) teens driving skills improved despite increased exposure to complex driving conditions, but secondary tasks also increased. Opportunities remained for improving the quality and variability in supervision and enhancing the development of skills during the lengthy period of practice.

Effects of age, system experience, and navigation technique on driving with an advanced traveler information system.

This paper explores the effects of age, system experience, and navigation technique on driving, navigation performance, and safety for drivers who used TravTek, an Advanced Traveler Information System. The first two studies investigated various route guidance configurations on the road in a specially equipped instrumented vehicle with an experimenter present. The third was a naturalistic quasi-experimental field study that collected data unobtrusively from more than 1200 TravTek rental car drivers with no in-vehicle experimenter. The results suggest that with increased experience, drivers become familiar with the system and develop strategies for substantially more efficient and safer use. The results also showed that drivers over age 65 had difficulty driving and navigating concurrently. They compensated by driving slowly and more cautiously. Despite this increased caution, older drivers made more safety-related errors than did younger drivers. The results also showed that older drivers benefited substantially from a well-designed ATIS driver interface.

Human factors field evaluation of automotive headway maintenance/collision warning devices.

Three on-road studies were conducted to determine how headway maintenance and collision warning displays influence driver behavior. Visual perspective, visual perspective with a pointer, visual perspective combined with an auditory warning, discrete visual warning, and discrete auditory warning were assessed during both coupled headway and deceleration events. Results indicate that when drivers are provided with salient visual information regarding safe headways, they utilize the information and increase their headway when appropriate. Auditory warnings were less effective than visual warnings for increasing headways but may be helpful for improving reaction time during events that require deceleration. Drivers were somewhat insensitive to false alarm rates, at least during short-term use. Finally, and most important, driver headway maintenance increased by as much as 0.5 s when the appropriate visual display was used. However, a study to investigate the longterm effects of such displays on behavior is strongly recommended prior to mass marketing of headway maintenance/collision warning devices.

Anti-lock brake system: an assessment of training on driver effectiveness.

When activated correctly, Anti-Lock Brake Systems (ABS) can provide drivers with the ability to stop a vehicle in shorter distances and allow for more vehicle control under heavy braking than conventional brake systems. This is especially true under wet or icy road conditions. However, it is believed that many drivers are either unaware of the correct method of activation or they revert back to the old method of pumping the brakes when they are faced with a hard braking situation. This paper examines the effectiveness of implementing low-cost training methods for alerting drivers to the correct brake activation technique. A 4-page, color training pamphlet was developed and subjects were given a short period of time to read it over before being asked to drive on an icy test track. Results indicated that those subjects who received the training were able to stop in shorter distances in a straight line braking event and more often used the correct brake activation technique than those subjects who did not receive the training. However, the stopping distance benefits were not realized in the curved and surprise braking events. These results suggest that the transfer of verbal knowledge may have value as a means for solving the apparent problem of improper ABS usage. However, some additional research should be done to validate these results. Since this experiment was conducted directly after the material was read, the possibility exists that without reinforcement, the trained braking techniques might become extinct in a short period of time.

The effects of compliance cost and specific consequence information on the use of safety equipment.

The effects of compliance cost and warning content on the use of protective eyewear by racquetball players were evaluated. Four-hundred-twenty subjects were observed for use of eye protection in a field setting. Results indicate that proximal placement of eyewear and the inclusion of specific consequence warning information increased safety equipment use. Implications of this research for augmenting warning effectiveness and safety are discussed.

Interactivity, information, and compliance cost in a consumer product warning scenario.

The effects of information content, physical interactivity, and cost of compliance on safe behavior of 356 subjects were examined using a common consumer product. The use of gloves for a "new formulation" consumer cleaning product was tested along with subject perceptions of the risk associated with the product's use. Results indicated that cost of compliance was the only variable that significantly affected the safe use of the product. Implications for consumer product safety and regulation are discussed.

Development of models for on-board detection of driver impairment.

Two of the leading causes of automobile accidents are driver impairment due to alcohol and drowsiness. Apparently, a relatively large percentage of these accidents occur because drivers are unaware of the degree to which they are impaired. The purpose of this research was to develop models, utilizing changes in driver behavior, which could detect driver impairment due to alcohol, drowsiness, or the combination of alcohol and drowsiness, and which could be practically implemented in an automobile. A computer-controlled automobile simulator was used to simulate a nighttime highway driving scenario for six drivers who participated in each of four conditions: a control condition, an alcohol condition, a sleep-deprived condition, and a combined alcohol and sleep-deprived condition. The results indicated that a useful on-board drowsiness detection device is possible and practical for highway driving. The results also showed that on-board alcohol impairment detection may be possible at levels below the legal driving limit in most states (BAC 0.1%).