An analysis of SafeLane Surface Overlay's performance during the 2005-06 winter season, conducted by a leading snow and ice control authority, concludes that Cargill's patented bridge and pavement treatment is providing safety and mobility benefits where it's being used, while requiring significantly less chemical treatment during winter storms.
The report by Asset Insight Technologies, a consulting service for the winter highway maintenance industry, summarizes SafeLane Surface Overlay's performance at all nine test installations across six states, as far north as Wisconsin and as far south as Texas.
"For statistically significant results, safety studies need to be conducted over a number of years," says Wilfred Nixon, president of Asset Insight Technologies and professor of engineering at the University of Iowa. "While this data is preliminary, it appears that the improved performance of the SafeLane overlay does indeed translate into safety improvements for the traveling public."
The report concluded that:
- In nearly all cases, test sections remained clear of snow or ice at times when it was accumulating on untreated (control) sections of roads and bridges.
- When accumulation did occur on test sections in heavy snowstorms, the snow and ice did not bond to the surface, resulting in easier plowing.
- Bare pavement could be maintained on test sections with about half the chemical applied to the untreated (control) sections.
- There were no concerns with chemical slickness or slipperiness even when chemical was applied in conditions where such slickness could be expected.
- There were no weather-related accidents at the nine installation sites over the winter season (a very small number of slide-off incidents in Ohio were attributed to excessive speed). In many cases this contrasted with several accidents on nearby untreated stretches of road or bridge deck, and in nearly all cases the treated sites themselves had a history of winter weather accidents.
A sampling of the data:
- In four separate snow events in South Bend, IN, officials reported that the SafeLane test sections of the Ironwood Bridge did not require treatment despite the other stretches being snow covered.
- In Superior, WI, the treated section of the Blatnick bridge "holds the chemical longer and when it does become snow covered, seems to have more traction than the surrounding area," according to one official.
- A three-day ice storm produced no accidents on the treated section of the McLean Bridge (McLean, TX) despite accidents "up and down the interstate," including one on the untreated side of the bridge.
- An exit ramp in Brecksville, OH, site of 49 accidents during the previous two years, saw "fewer slide off accidents" and a very easy application process.
SafeLane Surface Overlay is made up of a patented combination of epoxy and aggregate rock. Liquid de-icer is applied to the overlay before ice or snowstorms hit. The material acts like a rigid sponge, storing the chemicals inside, then automatically releasing them as conditions develop for the formation of ice or snow.
"This proactive approach protects bridge decks and roadways against frost and ice without the need to send work crews out in the midst of icy weather," says Bob Persichetti, general manager for SafeLane Surface Overlay at Cargill, which licenses and markets the system and which commissioned Nixon to conduct the study.
Safelane's patented technology is licensed to Cargill by Michigan Tech University, where it was invented by Russ Alger, director of MTU's Institute for Snow Research. The university is on Michigan's Upper Peninsula, where the lake effect produces up to 25 feet of snow per year — obviously an ideal location for such research.