The Nudge Effect: Enhancing Road Sign Comprehension with Billboards

Abstract: Road signs and billboards play a crucial role in enhancing road safety by providing crucial information and are effective platforms for conveying important messages, emphasizing the dangers of distracted driving, speeding, and drunk driving, contributing to a safer driving culture. Despite existing research on traffic sign installations, there is a limited focus on sign comprehensibility, which is influenced by cognitive factors, individual perspectives, and social influences. Numerous studies highlight the need to evaluate and improve sign comprehension. This study incorporates the nudge theory principles to assess the comprehensibility of traffic signs by strategically placing engaging billboards using a self-reported driver decision-making questionnaire (DDQ) survey. The study examines both quantitative and qualitative aspects, showing that both ‘fear’ and ‘humour’ can effectively nudge driver response. The quantitative analysis highlights that factors like ‘driving experience’; ‘follow road signs’ and ‘billboards nudge impact’, have a greater influence on speed reduction. Scenario II with fear-based messaging billboards (prescriptive decision-making model) achieved the highest compliance rate (91.89%), showing the stronger impact of emotional appeals in altering driver response. Meanwhile, qualitative findings suggest that while fear prompts an immediate response, humour could have a longer-lasting effect on encouraging drivers to reduce speed in the future as per the self-reported survey. Understanding changes in driver response related to road signs and informatory billboards could inform policy decisions on using billboards for enhanced road safety and responsible driving practices.