To obtain detailed information on driving exposure in the province of Ontario, a survey of 12,019 drivers, stratified by age, sex and region of the province, was carried out in the fall of 1988, using a mailed trip log. The survey instrument was based on that used in Quebec in 1985-6. Among drivers aged 16-24, 50% were sent one- and 50% three- day trip logs. Drivers aged 25- 29 all received a one-day log; in this age group, 504 received a road map as an incentive gift. A second subsample of 504 were given the option of responding by telephone if they preferred. Drivers over 60 all received a three-day log. Drivers failing to respond after six weeks were sent a short questionnaire to probe non-response. After excluding drivers who had died, moved or reported no longer driving, 10,164 eligible drivers remained. The return rate of completed questionnaires among these drivers was 36.3%. A detailed breakdown of differences in response rate by age group, sex and region indicated complex differences in these factors; comparison by targeting strategy (map, telephone option and log-length) provided evidence that shorter diaries have a small increase in return rate, and that the incentives used have either no effect (phone) or an effect (map) which differed for male and female drivers.
Samenvatting