A Study to Evaluate the Effectiveness of Signage and Equipment Installation for Traffic Speed Warning using the Analytical Hierarchy Process (AHP)

Abstract

Thailand has one of the highest road accident rates globally, with speeding as the primary cause, accounting for 76.78% of all highway accidents in 2022. Other contributing factors include non-compliance with traffic regulations, drunk driving, and inadequate infrastructure. To address this issue, Over Speed Warning (OSW) systems have been developed and play a crucial role in encouraging drivers to reduce speed, particularly in high-risk areas such as curves and slopes. These systems are designed to be highly visible and equipped with automated speed detection technology, significantly enhancing road safety and reducing the frequency of accidents.

      However, the effectiveness of OSW systems depends on several factors, including driver behavior, sign clarity, and environmental conditions. Research on the design and installation of OSW systems is essential for developing appropriate accident prevention strategies. Insights from such research can support decision-making in selecting the most effective warning systems for different locations, ultimately contributing to sustainable improvements in road safety across Thailand.

      Based on the evaluation of alternatives for installing speed warning signs, the "Your Speed" sign received the highest overall score (0.296) and demonstrated suitability across all key dimensions, including driver perception, clarity of conveyed information, and the potential to reduce accidents. Thus, it is considered the most outstanding option overall. Meanwhile, the "Over Speed Warning" sign (score 0.261) showed strong capability in raising drivers' awareness of their speed, although it has some environmental limitations. The "Speed Limit" sign (score 0.238) exhibited strengths in terms of driver familiarity, ease of understanding, and reasonable cost-effectiveness. In contrast, the "Speed Warning" sign (score 0.205), while offering low installation and maintenance costs, was found to be less effective in influencing driver behavior change, resulting in its ranking as the least preferred option.