EVALUATION OF URETHANE AND CARBIDE-TIPPED BLADES ON WHEEL-SUPPORTED SNOW PLOWS

The objective of this study was to evaluate the performance of urethane and carbide-tipped snow plow blades on wheel-supported plows. Their performance was compared to that of the Virginia Department of Transportation's (VDOT's) standard blade arrangement: carbide-tipped blades on plows without wheels. Performance was measured by the extent of damage to pavement markings, the quality of snow removal, and cost. The addition of wheel supports to plows with carbide-tipped blades prolonged the retroreflectivity and service life of pavement markings. A life-cycle cost analysis revealed that carbide-tipped blades without wheels were the least expensive alternative, followed closely by carbide-tipped blades with wheels, and then urethane blades with wheels. When compared with carbide-tipped blades without wheels, carbide-tipped or urethane blades with wheels were effective in removing loose, but not packed, snow. Timely chemical application to prevent snow-pavement bonding is crucial, particularly with wheel-supported plows. Urethane blades are susceptible to wear through friction and are impractical for use on second and third priority snow routes where variations in cross slope and soft shoulders bring the blade into contact with the pavement. The use of supports on plows equipped with carbide-tipped blades allows the operator the option to use the plow in a supported mode for first priority routes and an unsupported mode for second and third priority routes. Proper alignment of the wheels is critical to ensure proper operation, protection of the urethane blades from wear, and reduction of damage to pavement markings. Measuring the monetary value of increased and prolonged retroreflectivity of pavement markings and more effective snow removal is difficult. The authors recommend that VDOT not use urethane blades as a replacement for carbide-tipped blades under current operating conditions. However, if VDOT continues to make brighter and more durable pavement markings a high priority, then it should consider using carbide-tipped blades on plows with wheels. Other actions that balance protecting Virginia's pavement marking investment and ensuring effective snow removal, such as restricting the use of heavy equipment for snow removal and providing operator training, should also be considered. Finally, if supported plows are adopted for use, other options to support the plow should be investigated through product evaluations by VDOT personnel.