Use of Abrasives in Winter Maintenance at the County Level

Abstract

The use of abrasives in winter maintenance is a well-established practice. Typically, sand is placed on the road in amounts up to 340 kg/lane-km (1,200 lb/lane-mi). The sand is intended to increase friction between the vehicles and the often snow- or ice-covered pavement. Yet very little information exists on the value of sanding as a winter maintenance procedure. What information does exist tends not to support sanding as a process. Studies suggest that at highway speeds sand is swept off the road by relatively few vehicle passes (8 to 12) and that friction gains from sanding (when the sand remains on the road) are minimal. There are increasing environmental concerns about sanding. Some U.S. cities have already stopped sanding because of air quality concerns. Others are required to clean up all sand as soon as possible after application, using street sweepers. The state of the practice of abrasives usage in Iowa counties is reviewed. On the basis of these practices and the existing studies on abrasives usage, an attempt has been made to categorize the practices into three classifications: appropriate, questionable, and inappropriate. The choice of these categories for each practice is discussed. The classification of practices suggests that significant changes may be needed in regard to abrasives usage in winter maintenance. The nature of these changes is presented and discussed.