Crews have wrapped up another successful chip seal season in Ada County.
The Ada County Highway District completed 294 lane miles of chip seal this summer. This year, crews focused on Zone 2 South, which includes Meridian, south of I-84.
Because of the lack of temporary manpower resources due to COVID-19, ACHD combined what would normally be two crews into one crew. The crew completed all the arterial and collector roads and 50 percent of the residential roads in the area.
"It was a different year with a lot of challenges, but our crew really came through," said Jennifer Berenger, Deputy Director of Maintenance. "Not only were there great lessons learned, there are techniques we used this year that will persevere for seasons to come."
Zone 2 was originally scheduled for chip sealing in 2020 before operations were suspended due to COVID-19 concerns. Crews instead worked on backlog maintenance projects.
Next year, crews are scheduled to focus on Zone 3, which covers Kuna and southern Ada County.
Chip sealing is a cost-effective way to extend the life of Ada County's roads. Roads naturally break down as the oil in the road starts to oxidize. Traffic, weather and weight also break the roads down, eventually causing cracks and deterioration. By applying the chip seal, crews can go a longer time in between replacing roadways.
Chip sealing in Ada County is broken down into six zones, and crews typically work on one zone each year. Crews chip seal all arterials in the zone, and half of the residential roads in that zone. Arterial roads are scheduled for chip sealing every six years, while residential roads are chip sealed every 12 years.
To chip seal, crews first apply a filler into cracks to keep water from seeping into the base. Sweepers remove debris from the road, then a distributor truck lays down oil. A spreader box drops down the chips. Pneumatic rollers, along with local traffic, help push the chips down as the emulsion hardens. Once hardened, sweeper trucks remove the loose chips and crews apply a fog seal over the road. Lastly, paint crews restripe the roadway.