Driving difficulties among male adolescents.

Abstract

To the Editor: Automobile crashes are the leading cause of death among adolescent males [1Patel D.R. Greydanus D.E. Rowlett J.D. Romance with the automobile in the 20th century Implications for adolescents in a new millennium.Adolesc Med. 2000; 11: 127-139PubMed Google Scholar]. One of the most dangerous driving maneuvers is making left turns [2Clarke D.D. Ward P.J. Jones J. Overtaking road accidents Differences in maneuvering as a function of driver age.Accident Analysis Prevention. 1998; 30: 455-467Crossref PubMed Scopus (100) Google Scholar]. Making a turn is preceded by four steps: (a) detecting the presence of cross-traffic, (b) estimating the time of cross-traffic arrival, (c) evaluating the risk of being hit by cross-traffic, and (d) deciding whether to go or not go. We hypothesized that, compared to experienced middle-aged male drivers, adolescent male drivers would: (a) recognize driving-relevant cues more slowly, (b) over-estimate the time it would take for a cross-traffic car to arrive at their intersection, (c) judge the probability of being hit as less likely, and (d) judge that cross- traffic could get closer before deciding not to turn in front of it. Fifteen male high school drivers (mean age = 16.8, ± 1.0 yrs) and 15 adult male drivers (mean age = 40.5, ± 9.5yrs) participated. Adolescents drove significantly fewer miles/year (4888 ± 300 vs. 12,771 ± 175, p < .01), but had significantly more violations /1,000,000 miles driven (143.2 vs. 7.8, p < .001) and crashes (61.3 vs. 0, p < .001) in the past 2 years. Subjects viewed two different videoed scenarios of a car driving at a constant speed of 30mph, coming from the horizon to the intersection where the subject “sat.” Subjects were instructed to indicate when they first saw the car appear on the screen. Next, each video was played 3 more times, and subjects were instructed to say “yes, yes, yes” and eventually “No” when the car had gotten too close that it was no longer safe to make a left turn in front of it. Repeated testing assessed reliability. To assess risk appraisal, the car in both videos approached from the right and stop at the same fixed point. Subjects were instructed to estimate how long it would take the car, driving at the same speed, to reach their intersection. Finally subjects were instructed to rate on a 0 to 6 scale the likelihood of being hit by the car if it continued at the same speed and the subject turned in front of it. Compared with adults, adolescent drivers detected the appearance of the cross-traffic car significantly more slowly in both videos (p’s < .02), and allowed the car to get significantly closer for all three trials of both videos (p’s < .04–.001). On average, Adolescents drivers allowed the cross traffic to get 1.6 seconds closer (30mph= 0.5miles/min = 2640ft = 44ft/sec × 1.6 seconds = 70.4ft closer). Consistent with survey findings [1Patel D.R. Greydanus D.E. Rowlett J.D. Romance with the automobile in the 20th century Implications for adolescents in a new millennium.Adolesc Med. 2000; 11: 127-139PubMed Google Scholar], the adolescents in this study had more violations and crashes than middle-aged drivers. This may be explained in part by our findings. Adolescents took longer to detect a driving stimulus, a car appearing on the horizon, in both videos. This replicated finding may reflect a lack of confidence in appraisal of driving stimuli. The repeated risky delay in deciding not to turn can not be explained in terms of differences in risk appraisal or judgement of intercept time. However this potential risky delayed decision-making may be off set by the observation that when executing left turns, younger drivers do it significantly faster than middle aged drivers [3Cox AB, Cox DJ. Compensatory driving strategy of older people may increase driving risk. [letter] [corrected and republished in] J Am Geriatr Soc 1998 Oct;46: 1325–26.Google Scholar]. It is not clear whether these findings generalize to other driving judgements, to real driving conditions, or to risk taking in general [4Jelalian E. Alday S. Spirito A. et al.Adolescent motor vehicle crashes The relationship between behavioral factors and self-reported injury.J Adolesc Health. 2000; 27: 84-93Abstract Full Text Full Text PDF PubMed Scopus (54) Google Scholar]. If future research confirms that such risky judgments are associated with greater risk of future accidents, then this would have implications for driver’s education. In driver’s education, such an assessment tool may be used to screen for accident-prone drivers. Additionally, driver’s education would need to focus on driving judgement, along with driving skills.