Self-Reported Exposure and Crash Involvement in Large Sample of Ontario Drivers Aged 79 Years and Over

Abstract

The Ministry of Transportation of Ontario conducted a pilot study to evaluate the effectiveness of a group education and information session for drivers aged 80 and over. Questionnaires on older drivers' self-awareness of risk were completed by 1,163 drivers aged 79 and over. The questionnaire asked several rudimentary questions about self-reported exposure and crash involvement. Answers to these questions are used to estimate the amount of driving and the frequency of crash involvement for very old drivers. The respondents' self-reports of the distance and days driven during the previous week and the number of crashes within the past 5 years are cross-classified by gender, age, season, examination center location, household size, self-reported medical condition, and self-reported medication use. The best predictors of self-reported distance driven during the previous week are gender, age, and the location of the driver examination center (the latter variable is a proxy for geographic location). The best predictors of self-reported crash involvement during the previous 5 years are the presence or absence of a self-reported medical condition and two variables used as proxies for the amount of driving. The results of a logistic regression analysis indicate that drivers reporting both a current medical condition and more driving exposure have a substantially higher crash risk. However, important limitations stem from the use of self-report data and the absence of data on the onset of a medical condition. These results, therefore, are tentative at best.