| In cold and snowy region like Hokkaido、 with wintertime comes the potential for slippery roadways. These winter conditions result in negatively affecting traffic performance on roadways. In order to counter these negative effects、 it needs achieving effective and efficient winter maintenance operations. Then、 to understanding the winter road condition accurately is important to conduct appropriate and efficient winter road management. Road maintenance personnel in Japan judge road surface conditions primarily by visual inspection. However、 there are limitations to the accuracy and objectivity of such inspection、 because winter road surfaces are affected in complex ways by the road structures、 the roadside environment、 weather and other factors. In addition、 some road surface conditions are difficult to accurately judge visually、 and judgments differ from one individual to another. [*]The Civil Engineering Research Institute for Cold Region has introduced the Continuous Friction Tester (CFT)、 a device that is capable of continuously measuring the friction of the road surface. We studied whether using the CFT for quantitative assessment of the winter road surface could improve winter road management. The friction of national highways has been monitored in the greater Sapporo area since 2007/2008 winter season.[*]Data acquired and accumulated by the CFT have been used to establish a database that is linked with digital maps、 and Winter Road Friction Monitoring System has been developed. The system can be used for various analyses of winter roads. Also、 a website with a user-friendly interface was developed to allow maintenance staff to easily browse the monitoring data、 and information has been provided on the web. [*]The study showed that continuous monitoring of road surface friction enables maintenance operators to quantitatively determine temporal and spatial changes in winter road surfaces. The Winter Road Friction Monitoring System developed in the study is expected to allow better decision-making on winter road management and better examination of the results of daily winter road maintenance operations. This study showed also that the system can analyze relationships between these and traffic congestion or accidents associated with winter road conditions. |
