A Randomized Field Trial of Smartphone-based Feedback to Encourage Safe Driving

Each week participants will receive a safe driving tip for one of the four behaviors via text message.

Each week participants will receive a text message showing their overall driving score (out of 100) and subscores for distraction, hard braking, fast acceleration, and speeding (all running averages). The scoreboard will indicate whether their scores have gone up, down, or stayed the same. The message will include a link to a dashboard.

Each week feedback will focus the participant's attention on the driving behavior with the greatest opportunity for improvement based on their baseline driving behavior. Participants will be assigned a goal for the week of a score 5 points (3 points in the case of Driver Focus) better than their baseline for that area. If they meet the goal, they will be given a new goal 5 points higher; if they fall short, they will be asked to try for the same goal again. If they improve sufficiently-or if their improvement stalls out-they will be assigned a new behavior to focus on.

By clicking the link in the feedback text, they will be able to view a weekly dashboard that provides detailed information about their baseline, best, last, and average scores for each of the four behaviors, plus descriptions of the four behaviors.

Same as standard study dashboard, except participants will see at the top of the dashboard how well they are doing relative to their weekly goals.

At the end of the 12-week intervention period, their overall driving score will be translated into a $0-$100 reward amount. For example, a participant with an overall driving score of 84 at the end of the intervention period would receive $84 in compensation.

Participants will be asked to select which driving behavior they want to focus on improving, and to set a goal for the week that is above their baseline score. If they meet the goal, they will be asked to set a new, higher goal; if they fall short, they will be asked to try for the same goal again. If they improve sufficiently-or if their improvement stalls out-they will be asked if they want to focus on a new behavior.