Best Practices for Road Weather Management Version 2.0
Evaluation of Automated Bridge Deck Anti-icing System
Driving in snow and ice can be dangerous. This is especially true on bridges. Under certain cold weather conditions, moisture on bridge decks freeze because of the open air flow under them while the adjacent roadway is unaffected. This creates potentially hazardous driving situations for motorists who may not be expecting a change of condition from the road to the bridge surface. To combat this problem, a bridge deck anti-icing system was installed on a bridge on southbound Interstate 75 at the north interchange to Corbin, Kentucky in October 1997. This system can be actuated early before ice and snow form on the bridge to create hazardous driving conditions. The 11 parapet-mountd/bridge rail-mounted spray nozzles per side treat the two travel lanes and the approach plate with an anti-icing agent. The system uses calcium chloride as the anti-icing agent and sprays eight gallons during each application for the entire bridge. This early chemical application prevents the formation of icy conditions on the bridge deck. After four winter seasons, the system had minimal problems associated with it. The system worked efficiently and as expected. However, because of the location on an interstate which is one of the first areas treated during snow maintenance operations and because the bridge is located in a part of the state that does not receive an abundant amount of precipitation, the system was not as effective as first anticipated. It is recommended that this system be used in the following areas and/or conditions: (1) crash prone areas, (2) isolated structures that require the deicing truck to travel an unreasonable distance to treat, (3) remote areas that are difficult to reach in bad weather, or (4) bridges over water which may be more susceptible to freezing moisture.
University of Kentucky, Kentucky Transportation Center
Closed Circuit Television (CCTV)
Environmental Sensor Station (ESS)
Dynamic Message Sign (DMS)
PDF files can be viewed with the Acrobat® Reader®.