Exploration of Color Patterns for Improving Work Zone Safety and Perception

Work zone safety remains a persistent concern in the United States. Color patterns are an effective way to provide visual information for drivers. Existing studies explored the colors of work zone elements, while how the color patterns impact the drivers’ perception, information processing, and overall safety in work zones is missing. Therefore, this study aims to systematically investigate color patterns based on human information processing theory to improve the overall safety and perception of Indiana work zones. Methodology of this study includes: (1) A literature review to summarize the current efforts; (2) Crash data analysis to identify the representative work zones; (3) Natural Language Processing (NLP) analysis to explore color-related root causes for work zone crashes based on Indiana crash data; (4) Interviews to propose the color-related countermeasures; and (5) Driving simulation experiment to evaluate the effectiveness of countermeasures. There are several key findings. First, the color-related root causes of work zone crashes in Indiana were proposed as follows: (1) poor visibility and brightness of color for work zone elements, (2) insufficient color contrast between work zone elements and the overall environment, especially in the areas of road geometry change and road surface conditions change, and (3) lack of changes in color for work zone elements in dangerous areas (e.g., entering the work zone, transition area, and road geometry and surface conditions change). Second, the effectiveness of proposed countermeasures was identified: (1) For lane closure scenario, fluorescent orange sign with orange LEDs was the most effective one in attracting attention (perception stage) and maintaining cognitive workload (cognition stage) during both daytime and nighttime as well as improving steering behaviors (action stage) during daytime. Fluorescent orange sign with orange beacon countermeasure was also effective in attracting attention during nighttime and maintaining cognitive workload during daytime. (2) For shoulder work scenario, fluorescent orange sign with orange LEDs was the most effective countermeasure in attracting attention and maintaining cognitive workload at night. Fluorescent orange sign with orange beacon countermeasure also helped attract attention during nighttime. Based on the findings, several recommendations were provided to improve work zone safety.