Beginning this week and lasting for most of the summer the Ada County Highway District will be chipsealing roads in the Kuna area. The locations will vary week to week but will stretch across the entire southern portion of Ada County generally south of Lake Hazel Road all the way to Swan Falls.
Tim Morgan, Superintendent of Cloverdale Maintenance told the Kuna City Council at their last meeting that there are over 600 lane miles they will be resurfacing this summer. These roads include city streets, farm roads and roads in subdivisions.
“In the past we used to rotate every nine years,” Morgan said. “Three years ago we switched to a six-year rotation.”
Rather than replace roads or resurface them, chipsealing protects roads for a greater time in-between crack-seal maintenance that happens every year. It is also much cheaper than resurfacing. An overlay, resurfacing with a several inch layer of asphalt, costs about $2 per square foot or $265,000 per mile compared to chipsealing at 22¢ per square foot, $23,000 per mile.
The process is simple. Workers spray liquid asphalt on the road and then cover it with a ¼” size gravel which is then rolled out evenly. This cures quickly and cars can drive on them within 15 minutes of application. The road cures overnight and the next morning a sweeper removes the excess chips. Workers return and “fogseal” the road that helps set the rock in place and prevent protect the chipsealed road. He explained the chemical process of mixing the oil soup that is applied to the gravel before it settles in and locks everything in place.
“It’s not a lot different than making gravy,” Morgan said.
He told the city council that they will clear out of the central Kuna area in time for Kuna Days and that they should be completely done by the end of August.
Highway 69 (Meridian Road) will not be chipsealed as the roadway is managed by the Idaho Transportation Department.
For more information and a video of chipsealing in action, visit www.achdidaho.org/Departments/MO/Chipseal.aspx.