By CHRIS HUBER, HOLLY EDMISTON
Rapid City Journal
RAPID CITY, S.D. (AP) — The South Dakota Department of Transportation is providing more grip so your car won’t slip on some of the Black Hill’s windiest roads.
They’re doing this using something called High Friction Surface Treatment. The South Dakota DOT is the first in the country to use the treatment to reduce road-departure crashes on curvy roads in winter conditions.
Statistics show the new treatment is leading to fewer crashes, and it has earned the department some national recognition.
Andy Vandel, DOT highway safety engineer, told the Rapid City Journal that the treatment is done by bonding an aggregate, made of calcined bauxite, to the roadway using an epoxy. Calcined bauxite is an alumina-based mineral that resists “polishing” better than standard road surfaces, said Vandel. Polishing can cause a loss of traction. The new material is thus ideal for sharp corners, where more traction is needed.
Vandel estimates the cost of each curve treated with this new material at roughly $150,000. He said the DOT has plans to add the material to other spots throughout the state in coming years.
Last year, the state applied the treatment at 15 sites in the Black Hills, concentrating on some of the highest-crash areas.
The 15 sites where the treatment had 21 winter-road-condition crashes a year on average in the five years before the project was started, including seven injury or fatal crashes. In one winter season, there was a total of one crash and zero injuries at these sites, according to DOT statistics.
“This project was the first demonstration in the country of how the technology of a high-friction surface treatment could be used to reduce road-departure crashes with winter road conditions as a contributing factor,” said Darin Bergquist, state Secretary of Transportation, in a release. “Driver safety is a high priority for the department, and the innovative use of this treatment is already reducing crashes and saving lives.”
Some of the areas that have got the new highway treatment include tight curves on U.S. Highway 14A in Boulder Canyon and a stretch of Interstate 90 near Tilford. U.S. Also receiving the treatment have been stretches of Highway 16 a mile west of the Keystone Wye Bridge and U.S. Highway 85 between Deadwood and Spearfish.
Officials at the South Dakota Highway Patrol said they have noticed a decrease in crashes at places where the new treatment has been applied.
“As the South Dakota Highway Patrol continues its mission to reduce overall traffic crashes, I am proud to see the South Dakota Department of Transportation taking such proactive steps toward a similar mission,” state Highway Patrol Capt. Jason Ketterling said in a letter supporting the DOT’s application. “Without their research into new roadway materials and their application of them, it is reasonable to believe we would have seen similar crashes from years before.