AASHTO Journal, 21 October 2011
“Traditional loops in the pavement required too-frequent replacement, and heavy trucks going to and from the nearby sugar beet processing plant were prematurely deteriorating the roadway surface,” ITD traffic manager Kevin Sablan said. “Loops would not last long enough, and using signals based on video detection also was problematic because of ‘fog,’ created in part by the factory.”
The cost benefit for the D-Tec system comes from its longevity, performance in fog, and lower maintenance costs since lenses on a video-detection system require frequent cleaning.
Idaho 52 SAFLEA: In August, a new treatment method was used on a section of Idaho 52 near Emmett in need of surface repair. A process called Stress-Absorbing Fiberglass Layer of Emulsified Asphalt was used to allow crews to apply a seal-coat finish to the surface layer, extending highway life.
The SAFLEA treatment strengthens and reinforces a traditional sealcoat by sandwiching two-inch-long chopped fiberglass strands between two layers of asphalt emulsion.
“After the emulsion and strands are applied, chip-seal aggregate is placed and rolled as normal,” ITD project engineer Jeff Morf. “The reinforced surface slows cracking and resists snowplow damage. Although the technology is somewhat new to Idaho and surrounding states, it has been used successfully in Europe the past two decades.”
Using the SAFLEA process on the 13-mile project cost only 20% more than a standard seal coat, while extending the life of the roadway another five to 10 years.
U.S. 95 Culvert Replacement: A little less than a year ago, ITD’s maintenance force faced an expensive repair to a large, plugged culvert under a section of U.S. 95 that needed to be replaced. A contractor estimated the repairs at $50,000, a higher amount than expected and difficult to justify in an environment of tight budgets.
Instead, ITD decided to look internally for a solution. ITD’s Special Crew and New Meadows maintenance finished repairs for a cost far below the initial $50,000 estimate.
“This was a very extensive project with little time to complete it,” ITD Special Crew foreman Dave Dansereau said. “We completed it in six days, working daylight to dark straight through to completion.”
Accordint to ITD, the department spent $6,500 to rent an excavator and $11,000 on materials and wages, for a total outlay of $17,500 — an example of making the dollar stretch in tight times.