Targeted nudging for speeding behavior: The influence of interpersonal characteristics on responses to in-vehicle road nudges.

Road carnage is one of the most fatal and expensive global issues today. Many solutions have been implemented to minimize it, but most are costly and unreliable. Therefore, in this study, nudges were used as a reliable and inexpensive tool to affect safe driving behavior which, in turn, may reduce road fatalities. To optimize the use of nudges, we suggested that responses to nudges - in a similar manner to responses to other stimuli - may vary by interpersonal characteristics, so that different nudges may lead to more accurate and reliable reactions in different sub-populations in a predictable manner. To test these assertions, we collected a sample of 200 participants, both men and women, ages 17.5 to 83 years. We measured different interpersonal characteristics that included both demographic information (e.g., age, gender, years with a driver's license) and different personality traits. We then assessed responses to nudges using a simulator that was specially designed for this study, in which participants are asked to adjust their speed as they see fit while they watched a video shot from a driver's perspective of the forward roadway. Over the course of the video, a different nudge was displayed for each subject and their response latency and speeds were recorded for further analysis. We were able to observe several interesting phenomena: responses to a reminder nudge and a negative reinforcement nudge were faster than responses to a social norm nudge. However, the latter showed a longer-term impact. The responses to the social norm interventions were also more variable, demonstrating that high neuroticism is linked to decreased response to social norm nudges, a picture that is repeated in men compared to women. Contrarily, conscientiousness was linked to a faster and more reliable response to the social norm nudge, and the gender effect was eliminated for men with high conscientiousness. Moreover, parenthood was found to increase the response to all nudges and was protective against the effects of high sensation-seeking, which led to more road violations. These findings may be tested using modern technology, which can facilitate the measurements of personal traits and verify the reliability of responses to nudges. Therefore, the current study suggests nudge personalization may be beneficial in improving the use of nudges on the road.