A comparison of web-based and telephone surveys for assessing traffic safety concerns, beliefs, and behaviors

The purpose of this investigation was to compare the results of a web-based and a telephone interview survey measuring driver concerns about a variety of traffic safety issues, their beliefs, and specific driving behaviors.

State-wide, annual random digit-dial telephone surveys and web-based surveys were conducted in Maryland. A total of 1,700 drivers were surveyed by telephone and 6,806 took a web survey.

Telephone respondents were more likely to be female and older. Web respondents were more likely to be white and not Latino/Hispanic. After controlling for demographic differences, telephone survey respondents were more likely to be concerned about traffic safety. They were more likely to believe that sobriety checkpoints reduce drunk driving (OR=2.18, 95% CI 1.94, 2.45), they would be ticketed for not wearing a seat belt (OR=1.26, 95% CI 1.12, 1.43), and they would be stopped by the police if they drove after drinking too much (OR=1.17, 95% CI 1.03, 1.32). They were less likely to report a variety of risky behaviors including using a cell phone while driving (OR=.54, 95% CI .48, .61) and driving 10+ mph over the speed limit (OR=.81, 95% CI .72, .91), but were more likely to report having been ticketed for a moving violation in the last month (OR=2.22, 95% CI 1.70, 2.90). Suggestions are offered for overcoming potential sources of sampling bias.

Web-based surveys produce substantially different results than random-digit-dial telephone surveys, when used for public assessments of traffic safety concerns and behaviors.