Evaluation of traffic sign retroreflectivity measurement using mobile LiDAR

辉固Roadware是一家总部位于密西沙加的公司，专门从事定制道路基础设施数据收集和处理解决方案。辉固Roadware是国际知名的创新和客户驱动的自动道路分析仪（ARAN）技术。ARAN技术在1980年中期首次发展。模块化的ARAN是一种用于路面数据收集的多功能车辆，目前已被世界各地的许多交通和基础设施机构采用。目前的ARAN系统在检测和评估反光交通标志质量方面的能力有限。反射率是与夜间能见度相关的因素之一，是材料将光线重定向回光源的特性。随着时间的推移，反光性能逐渐恶化，标志变得越来越少

Fugro Roadware is a Mississauga based company specializing in customized roadway infrastructure data collection and processing solutions. Fugro Roadware is internationally known for its innovative and customer-driven Automatic Road Analyzer (ARAN) technology. The ARAN technology was first developed in the mid-1980s. The modular ARAN is a multifunctional vehicle used for road surface data collection, and is currently employed by numerous transportation and infrastructure agencies around the world. The current ARAN system is limited in its ability to detect and assess the quality of retroreflective traffic signs. Retroreflectivity, one of the factors associated with night visibility, is the property of a material to redirect light back towards its source. As the retroreflective properties gradually deteriorate over time, the sign becomes less detectable and legible at night. Therefore, it is critical to keep monitoring the reflective status of signs and maintain their minimum retroreflectivity levels for regularity, warning, and guide signs. The most objective method to maintain traffic sign retroreflectivity is measuring sign retroreflectivity with handheld devices. However, this maintenance method, measuring reflectance with less representative geometry, is labour-intensive, time-consuming and exposes maintenance crews to risk. Thus a more automated, accurate and safer method of sign retroreflectivity measurement is urgently required. Recently Fugro Roadware integrates an emerging mobile lidar (light detection and ranging) scanner with ARAN system, which allows the company to rapidly collect high-density and accurate positioning and reflective intensity data along road corridors. In support of ongoing research and development of ARAN technology, this project aims to investigate the potential of mobile lidar scanners mounted on Fugro Roadware's ARAN system as an alternative measure of sign retroreflectivity, to the traditional sign maintenance process. The outcomes of proposed research will lead to a new development of laser-based analytic service for monitoring traffic sign retroreflectivity for Fugro Roaware.