雙效標線之長期績效與成本效益分析

Abstract

道路標線作為交通工程中至關重要的一環，主要負責指示、警告與禁制之管制交通目的，不僅能發揮反光性能清楚地提供道路資訊，同時也能保持抗滑性能避免用路人打滑，眾多研究亦指出良好的標線能有效降低交通事故數，顯示標線對於道路交通安全至關重要。然而因標線之反光與抗滑性能係分別仰賴玻璃珠與抗滑骨材等不同材料機制，兩者在性能表現上又存有物理性質之互制關係，故縱觀國內外皆鮮少有同時兼顧反光與抗滑之雙效標線研究。 為此本研究之研究目的係力求標線能兼顧優異的反光與抗滑雙性能表現，基於多次標線材料配比實驗，確定雙效標線甲料與乙料之內摻與外撒材料配比，於市區道路現地劃設並展開為期十二個月之回歸反射RL、擴散反射Qd、抗滑係數BPN標線性能長期追蹤檢測。研究結果顯示等比例混合料外撒之甲料不但保有充分的抗滑性能(BPN≥50)，更具有亮眼的反光性能(RL≥300 mcd/m2/lx)；而前後各自撒佈玻璃珠與抗滑骨材的乙料亦有良好的反光表現(RL≥200 mcd/m2/lx)，抗滑表現甚至與僅注重高抗滑之II型標線相當(BPN≥ 55)。同時根據國內外標線規範回顧與實驗數據支持，提出施工驗收與維護標準標線性能建議門檻。進而規劃標線試片外撒量成效實驗，隨著使用材料與外撒量變換分析其雙性能之成效差異與材料經濟性，作為日後標線材料之選擇建議。此外本研究亦建立標線性能指標作為標線性能之等級區分，並依照不同使用情境之性能需求評量標線之服務績效，得知雙效標線甲、乙料不論在日間或夜間、乾燥或多雨都能較一般II型標線提供更佳的服務績效。關於成本效益部分，雙效標線在郊區道路缺乏照明之環境中展露突出的反光性能，克服成本劣勢達到更佳的成本效益，可作為後續標線材料之推廣應用，以此提升道路標線之服務水準落實道路交通安全之目的。

Road markings play a key role of traffic engineering and perform crucial functions such as directing, warning, and regulating traffic. They provide vital road information through their reflective properties and ensure safety by preventing skidding. Numerous studies have shown that well-maintained road markings significantly reduce traffic accidents. However, achieving both high reflectivity and skid resistance in road markings presents a challenge due to the conflict between glass beads and anti-skid aggregates that enhance reflectivity and skid resistance, respectively. Therefore, very few research findings addressed this area. The objective of this study is to develop dual-performance thermoplastic road markings that offer superior reflectivity and skid resistance simultaneously. Through extensive material proportion experiments, two types of dual-performance marking materials, Types A and B, were identified. These markings were applied on urban roads and subjected to 12 months data collection along with the conventional type II thermoplastic marking. The coefficient of retroreflected luminance (RL), luminance coefficient under diffuse illumination (Qd), and skid resistance (BPN) were assessed. The results indicate that Type A, characterized by an equal mix of materials applied externally, maintained adequate skid resistance (BPN ≥ 50) and exhibited remarkable reflectivity (RL ≥ 300 mcd/m²/lx) after serving 1 year. Type B, which involved the sequential application of glass beads and anti-skid aggregates, demonstrated great reflectivity (RL ≥ 200 mcd/m²/lx) and outstanding skid resistance (BPN ≥ 55) which is even better than type II markings. Based on a comprehensive review of international standards and experimental data, threshold values for construction acceptance and maintenance were also proposed in this research. Additionally, experimental factor designs on the drop-on materials were conducted. The findings provide valuable information for future road markings selection. Performance indicators were established to classify road marking performance levels, assessing service performance according to different usage scenarios. The research revealed that dual-performance Type A and Type B markings offer superior service performance compared to type II markings under various environment conditions. Through cost-effectiveness analysis, dual-performance markings showcased outstanding reflectivity in area with insufficient street lights, such as country roads, even their unit costs are higher than type II markings. It indicates that dual-performance markings are a viable option for widespread application, aiming to enhance the service level of road markings and ultimately improve road traffic safety. The proposed materials and application methods present a practical approach for maintaining markings’ high performances under diverse conditions.