Date of this Version
NDOR Research Project Number SPR-P1(03) P557 Transportation Research Studies
The primary objective of winter maintenance operations is to improve traffic safety and efficiency during winter storm periods. Abrasives and salt brines have been successfully applied to increase traction and prevent snow and ice from bonding to road surface. However, because of some undesired side effects, such as corrosion and damage to the environment, salt and abrasives may need to be supplemented by other substances in some areas. Powerful non-corrosive acetate-based chemicals have been considered by several agencies, but their high price has limited their use. Recent research has focused on the use of new, less corrosive, and highly effective chemicals, such as liquid corn salt (LCS). This research project evaluates and compares the cost-effectiveness of using salt brine, and LCS on Nebraska highways. Field studies were conducted during the winter of 2002-2003 on two highway sections in Nebraska. Available field data included weather information, chemical use, time to achieve bare pavement, and maintenance log records. A benefit-cost analysis was performed to determine the cost-effectiveness of each treatment alternative. The operational benefits were the savings in road user costs resulting from reduction in travel time and delay. They were determined from field study data. The safety benefits related to accident reduction due to improved road surface conditions were not considered because of lack of accident data on LCS-treated roadways. The costs included material, labor and equipment costs. Material costs were determined from material usage data obtained from maintenance logs. Labor and equipment costs were estimated from relevant literature. The cost-effectiveness of salt brine and LCS were compared based on their benefit-cost ratios calculated over a range of ADTs and truck percentages. Guidelines were developed for the most appropriate use of these chemicals under various weather and traffic conditions.