Environmental Conditions Leading to Spontaneous Corrugation on Snowy-Icy Roads Due to Repeated Loading by Moving Vehicles

摘要

Spontaneous corrugation can occur at intersections on snowy and icy roads due to the repeated passage of moving vehicles. Corrugation adversely affects driving safety due to reduced friction between the wheels and road; it can also cause passenger discomfort and transform crosswalks into unstable surfaces for pedestrians. Because the causes and timing of spontaneous corrugation remain poorly understood, effective countermeasures cannot be applied to prevent its formation. In this study, we installed time-lapse cameras at an intersection in Sapporo, Japan, to observe the formation of corrugation in two consecutive winters (2015-2017). To determine the relationship between corrugation and environmental conditions, we obtained meteorological data from the observatory closest to the intersection and recorded the temperature distribution on the road using a thermographic camera. Our analysis showed that a threshold amount of fresh snowfall was necessary for corrugation. The air temperature required for corrugation was between 0 and -2° environment, snow, temperature, vehicle, washboard road C. Surface snow showed a tendency to thaw due to energy provided by heat transfer from the chassis of vehicles; thus, corrugation emerged at the headstream side of the traffic flow, where vehicles frequently stopped for red lights. As a result, corrugation can be predicted by forecasting environmental conditions. We also initiated a social network survey, where participants were asked to upload photographs of corrugation on snowy and icy roads to a website, along with the time and location. An analysis of these corrugation events and the associated environmental conditions supported our results. This study will contribute to improving the safety of winter travel in regions where spontaneous corrugation is common.