Driver Response to Dynamic Message Sign Safety Campaign Messages

About the report:

Messages like “May the 4^th be with you, text I will not” are increasingly used to catch drivers’ attention. The development and use of on-traditional safety messages are distinctly different than messages previously displayed on highway signs. These message attempt to provoke an emotional response and may reference themes like popular culture, sports, or use rhymes to increase their effectiveness. Unfortunately, there is little empirical evidence measuring how effective these messages are at changing driver behavior, or guidance on how to target messages for specific groups of people. The goal of this study was to understand what types of non-traditional safety messages are being displayed across the country, measure their effectiveness, and identify any potential negative impacts of these messages on rivers.

Non-traditional safety messages were collected from across the country and categorized by their intended behavior, intended emotional response, and message theme (e.g., sports, rhymes, pop-culture). To measure the effectiveness of these non-traditional safety messages, 300 people read 80 messages. Messages were grouped by their behavior, emotion, and theme. Participants were asked about their perception of these messages to change driver behavior, to identify the intent of the message, and to recall messages. Participants’ neuro-cognitive response when reading the messages was also observed. A neuroimaging instrument called functional near-infrared spectroscopy was used to quantify the differences in how non-traditional messages elicit cognitive attention among drivers.

The results indicate people perceive all types of non-traditional safety messages as effective. Messages about distracted driving and driving without a seat belt, messages meant to provoke a negative emotion, and messages using statistics are perceived to most likely change driver behavior. Gender, age, and driving behavior have a small effect on perception. Females are significantly more likely to believe non-traditional safety messages are effective compared to males. Drivers over the age of 65 compared drivers below the age of 65 are significantly more likely to believe non-traditional safety messages are effective. Low-risk and high-risk drivers compared to medium risk drivers are significantly more likely to believe non-traditional safety messages are effective.

Messages about general safe driving and general aggressive driving are significantly misunderstood compared to messages about distracted driving, impaired driving, and wearing a seat belt. Messages about distracted driving and impaired driving are the most recallable. Messages about distracted driving, messages with humor, and messages that use word play and rhyme elicit significantly higher levels of cognitive activation in the brain. An increase in cognitive activation is a proxy for increased attention. The highest level of cognitive activation when reading messages occurred in the region of the brain associated with emotional control and word processing. The younger the driver, the greater the increase in message engagement in this region of the brain.

These results provide evidence that drivers find non-traditional safety messages as effective, and specific messages are more effective than others. Messages about distracted driving, messages that include humor, and messages that use word play and rhymes rank high among multiple measures of effectiveness. Recommendations for creating new messages and targeting specific groups of people are provided.

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