SAND RECOVERY FOR HIGHWAY DRAINAGE DESIGNS

Roadway sanding is a common practice in cold regions because sand increases the roadway friction when mixing with snow. However, after snow melt, sand imposes potential hazards to traffic. Recovery of sand from highways has become an increasing concern not only for the reason of traffic safety, but also for being nonpoint pollution sources to nearby wetlands and streams. In this study, a snow storage element is introduced to the renascence project of a mountainous highway that is running through an environmentally sensitive forest area in Colorado. Recovery of winter sanding material from the highway is designed to be a joint effort of surface runoff and sweeping machines. As a tradeoff exists between sand recovery and the size of a snow storage area, this study also presents a maximization methodology by which the size of the snow storage area can be determined by the diminishing return of sand recovery.