Friedrich Trista E, Duerksen Kari N, Elias Lorin J
a Department of Psychology , University of Saskatchewan , Saskatoon , Saskatchewan , Canada.
Traffic Inj Prev. 2019;20(2):128-133. doi: 10.1080/15389588.2018.1549731. Epub 2019 Apr 2.
The accuracy of self-reported driving exposure has questioned the validity of using self-reported mileage to inform research questions. Studies examining the accuracy of self-reported driving exposure compared to objective measures find low validity, with drivers overestimating and underestimating driving distance. The aims of the current study were to (1) examine the discrepancy between self-reported annual mileage and driving exposure the following year and (2) investigate whether these differences depended on age and annual mileage.
Two estimates of drivers' self-reported annual mileage collected during vehicle installation (obtained via prestudy questionnaires) and approximated annual mileage driven (based upon Global Positioning System data) were acquired from 3,323 participants who participated in the Strategic Highway Research Program 2 (SHRP2) Naturalistic Driving Study.
A Wilcoxon signed rank test showed that there was a significant difference between self-reported and annual driving exposure during participation in SHRP 2, with the majority of self-reported responses overestimating annual mileage the following year, irrespective of whether an ordinal or ratio variable was examined. Over 15% of participants provided self-reported responses with over 100% deviation, which were exclusive to participants underestimating annual mileage. Further, deviations in reporting differed between participants who had low, medium, and high exposure, as well as between participants in different age groups.
These findings indicate that although self-reported annual mileage is heavily relied on for research, such estimates of driving distance may be an overestimate of current or future mileage and can influence the validity of prior research that has utilized estimates of driving exposure.
自我报告的驾驶暴露情况的准确性对使用自我报告的里程数来回答研究问题的有效性提出了质疑。与客观测量方法相比，研究自我报告的驾驶暴露情况准确性的研究发现其有效性较低，驾驶员会高估或低估驾驶距离。本研究的目的是：（1）检查自我报告的年里程数与次年驾驶暴露情况之间的差异；（2）调查这些差异是否取决于年龄和年里程数。
从参与战略公路研究计划2（SHRP2）自然驾驶研究的3323名参与者中，获取了在车辆安装期间收集的驾驶员自我报告的年里程数的两个估计值（通过研究前问卷获得）以及近似的年驾驶里程数（基于全球定位系统数据）。
Wilcoxon符号秩检验表明，在参与SHRP2期间，自我报告的和年度驾驶暴露情况之间存在显著差异，无论检查顺序变量还是比率变量，大多数自我报告的回答都高估了次年的年里程数。超过15%的参与者提供的自我报告回答偏差超过100%，这是那些低估年里程数的参与者所特有的。此外，低、中、高暴露水平的参与者之间以及不同年龄组的参与者之间，报告偏差也有所不同。
这些发现表明，尽管研究严重依赖自我报告的年里程数，但这种驾驶距离估计可能高估了当前或未来的里程数，并可能影响先前利用驾驶暴露估计的研究的有效性。
