Method to Assess Efficiency and Improve Design of Snow Fences

Abstract

Blowing and drifting of snow is a major concern for transportation efficiency and road safety in regions where their development is common. One common way to mitigate snow drifts on roadways is to install plastic snow fences. Of critical importance for road safety is protection against snow drifting in regions with narrow rights of way, where standard fences cannot be deployed at the recommended distance from the road. The current study proposes a joint experimental and numerical approach to monitor snow deposits around snow fences, and to quantitatively estimate snow deposits in the field, assess efficiency, and improve the design of snow fences. Snow deposit profiles were mapped using global positioning system–based real-time kinematic surveys conducted at the monitored field site during and after snow storms. The monitored site allowed testing various snow fence designs under close to identical conditions. A main goal of the current study was to assess the performance of lightweight plastic snow fences with a lower porosity than the typical 50% porosity used in standard designs of such fences. The field data, collected during the first winter, were used to identify the best design for snow fences with a porosity of 50%. The flow fields obtained from numerical simulations showed that the fence design that worked the best during the first winter induced the formation of an elongated area of small velocity magnitude close to the ground. This information was used to identify other candidates for optimum design of fences with a lower porosity. Two of the designs with a fence porosity of 30% that were found to perform well based on the results of the numerical simulations were tested in the field during the second winter along with the best performing design for fences with a porosity of 50%. The field data showed that the length of the snow deposit away from the fence was reduced by approximately 30% for the two proposed lower-porosity (30%) fence designs compared with the best design identified for fences with a porosity of 50%. Moreover, one of the lower-porosity designs tested in the field showed no significant snow deposition within the bottom gap region beneath the fence. It is expected that this design will continue to work well for even more severe snow events or for successive snow events occurring during the same winter. The approach advocated in the current study allowed making recommendations for optimizing the design of lower-porosity plastic snow fences. This approach can be extended to improve the design of other types of snow fences.