A Bridge Deck Anti-Icing System in Virginia: Lessons Learned from a Pilot Study

About the report:

The need for this project originated with Virginia Department of Transportation's (VDOT) plans to widen and replace a number of bridges along Route I-95. Many of the bridge decks in the new facilities will be in the shade, which will increase the probability that maintenance crews will have to respond to icy conditions. Various anti-icing technologies have shown promise, but most still require personnel to travel to the site of icing problems to treat them. Fixed automatic spray technology (FAST) is an exception. FAST is the application of a liquid chemical freezing-point depressant using an in-place, mechanical, spray system The purpose of this study was to evaluate the automatic anti-icing spray technology for bridge decks and become familiar with the construction, maintenance, and operations issues involved with such systems. The study evaluates a number of design options for delivery of a liquid chemical to the deck to determine the effectiveness of the options. For the purposes of this report, effectiveness is defined in terms of timeliness of operation, appropriateness of response, achievement of desired results, and a benefit-cost ratio greater than 1. The report recommends that VDOT consider FAST an option for initial delivery of deicing chemicals to road and bridge travel lanes and develop criteria for prioritizing FAST installations that consider savings for reduced accidents and congestion. Recommendations are also made for nozzle and surface sensor design and location based on lessons learned from the pilot project.

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