I-94 bridge in Minnesota getting de-icing technology

SafeLane system expected to be more effective than typical spray systems

June 26, 2007

Work began to apply a new de-icing technology to the I-94 bridge near Barnesville, Minn. despite 90º temperatures earlier this week, according to a report in The Forum.

The Minnesota Department of Transportation (MnDOT) is implementing the new technology to help prevent dangerous ice and frost formation on the interstate that contributes to winter accidents, according to the newspaper.

“We wanted to try something different to cut down on crashes,” said Tom Swenson, the district traffic engineer for MnDOT. “We hope it makes a difference.”

MnDOT chose to install the system at the Barnesville bridge as well as at the I-94 bridge near Alexandria last week, because of its history of crashes, the newspaper reported.

In the past five years, an average of four or five crashes has occurred on the bridge near Barnesville, Swenson said. Of those, 70 to 80% were during winter.

“To have that many crashes in that short of a space stood out to us,” Swenson said.

The de-icing technology will be installed on a total of 3,000 ft: the roadway before the bridge, on the bridge’s surface and the roadway after the bridge, according to The Forum.

Installation of the de-icing system in Alexandria and Barnesville cost about $400,000, Swenson said. Depending on the weather, the de-icing installation in Barnesville should be completed by June 28, the newspaper reported.

The new technology, SafeLane, which is licensed and marketed by Cargill, consists of an overlay that acts like a sponge, storing de-icing chemicals and automatically releasing them as snow and ice develops.

SafeLane also helps create friction with its epoxy and aggregate combination, which has more skid friction than conventional pavement, Swenson said.

The new overlay is expected to be more effective than typical spray systems, and the system should last about 20 years, said Bob Persichetti, the general manager of SafeLane.

Once winter arrives, workers will have to put down the de-icing chemical about twice per month to keep the system working, Persichetti said, and the chemical will last through several snowfalls.

De-icing systems installed along Highway 336 in Dilworth, Minn. in 2004 experienced a few glitches during their first year, the newspaper reported., and the I-94 bridge over the Red River failed to work in certain conditions in 2006.

Research by Michigan Technological University and a report by Asset Insight Technologies, both in partnerships with Cargill, confirm the effectiveness of the new epoxy aggregate overlays at clearing ice and increasing mobility, according to The Forum.

The SafeLane system has been used at 31 sites in 18 states. The de-icing technology was installed on a bridge in Hibbing, Minn., in July 2006, the paper reported. Persichetti said another installation project is planned for Bemidji, Minn., the week of July 16.

“There’s going to be a demand in areas (for this),” Swenson said.

Last year, ice or packed snow contributed to 5,516 crashes and 37 fatalities, according to a report released by the Minnesota Department of Public Safety.