Top Projects 2019: Transportation Projects

US-12 Tumble Creek and US-12 Warm Springs

At a special awards event held on Thursday, Sept. 19, the project was awarded First Place in the Transportation Projects category by the Idaho Business Review. The publication is available for free download.

This project, which included 49.87 miles of cold milling, plant mix overlay, signs and guardrail adjustments, was located within one of the most remote areas in Idaho. The team overcame significant challenges, including major difficulties with communication. This became particularly difficult with more than 50 trucks running at different points in the project, which stretched out for more than 50 miles from the hot plant.

In this large, two-part project, Knife River Corporation and the Idaho Transportation Department worked together to minimize traffic impacts and maximize the duration motorists could spend on the highway. Even with a change order, the team completed the project 28 working days ahead of schedule.

The scope of work included the milling and removal of approximately 741,550 square yards of existing asphalt pavement and placing of approximately 149,915 tons of HMA CL SP-3.

Additionally, 11,940 lineal feet of guardrail was removed and replaced and there were soft spot repairs, new centerline rumble strips, pavement markings, new roadway signs, materials testing, survey, and the use of a pilot car for the traveling public.

With the material source 50 miles from the plant site and a very small area for stockpiling aggregates and equipment, Knife River had to work with multiple trucking systems to keep the project supplied, but not overfill the site. This took a high level of communication between groups in a location that did not allow cell phone service or email. Because mobile phone service was available only 40 miles from either end of the project, Knife River turned to 1980’s tactics (via haul truck messengers) for passing messages.

As this is a busy bicycle touring route and bicyclists could not keep pace with the pilot lines, Knife River Corporation also used offseason raft transport busses for transporting cyclists through the extended work zone.

This was very successful and did much to gain positive press on the project.

Manning Crevice Bridge Replacement

The project was awarded Second Place in the Transportation Projects category by the Idaho Business Review.

This once-in-a-lifetime project replaces the original Manning Crevice Bridge built in the 1930s. The severely deteriorated one-lane, one-span, 240-foot suspension bridge had limited width, height, and load capacity, along with extremely tight turns at each approach that severely limited the type of vehicles that could cross.

The bridge crosses the Salmon River and is adjoined to the north by the Nez Perce National Forest and to the south by the Payette National Forest. The river corridor is the major economic base for the Riggins area.

The new bridge is a 300-foot span, 75- foot single tower, cable-stayed, asymmetric suspension bridge that was built adjacent to the existing bridge. The team worked carefully to maintain the flow of traffic both over the bridge and on the river itself. Two critical constraints were access to the project site via the one-lane Salmon River Road and limited access due to the steep rock faces of the Salmon River canyon.

The stunning and remote location and rare asymmetrical design make this bridge a work of art, and completion of the new bridge provides improved access to the National Forest and Frank Church Wilderness area and supports the growth of businesses, forestry and river recreation.

Williams Creek (Shoup) Bridge Replacement

The project was awarded Third Place in the Transportation Projects category by the Idaho Business Review.

This project was a reconstruction of the Shoup Bridge and approximately 1,380 feet of Forest Highway 21, better known as Williams Creek Road. Shoup Bridge is the primary access point to the central portion of the Salmon-Challis National Forest, private property and commercial mining operations on the west side of the Salmon River.

The new Williams Creek (Shoup) Bridge is an updated, dual-lane, single-span structure utilizing an arched steel-and-suspension cablesupport system.

The team used an ACROW temporary bridge structure for traffic during demolition and construction of the new bridge in order to keep traffic flowing. It also implemented an alternate approach for structural steel erection that provided environmental and schedule benefits to the project. This working structure allowed for the use of aerial lifts, materials staging and manpower to access parts of the bridge that would have otherwise required an additional work platform to be constructed adjacent to the bridge using a pile system and thus disrupting more of the highly protected Salmon River.

I-84 Karcher to Franklin

The project was awarded Honorable Mention in the Transportation Projects category by the Idaho Business Review.

This project involved the widening and reconstruction of I-84 between the Karcher/ Midland and Franklin Boulevard interchanges in Nampa. In preparation for this work, the existing shoulders of I-84 had to be widened to add temporary lanes on which to shift traffic as the new, permanent lanes were constructed.

Work included the construction of 3.4 miles of temporary shoulder along I-84 to facilitate future widening. The scope comprised milling of existing asphalt, excavation, import and placement of base and subbase and 17,500 tons of asphalt paving, plus the placement of more than 6,700 linear feet of concrete barrier.

The team had to work overnight in especially chilly November weather, and adhered closely to safety requirements.

The team also introduced innovations. The transportation department introduced an application developed in Minnesota called PaveCool (V3.0) for cold temperature paving. The calculator factors things including wind speed, temperature and thickness to determine the delivery temperature of the materials. It was successful and the team met its quality goals in part due to this application.