Idaho Bridge Work To Close U.S. 95 For Three Days Construction Near Riggins To Force North-South Travelers Onto Washington, Oregon Routes

The flow of traffic through Idaho’s north-south artery will be cut off this weekend.

That’s because major surgery is under way on the U.S. Highway 95 bridge north of Riggins.

The 61-year-old Goff Bridge will be raised, rolled and repositioned 65 feet to the west. It will serve as a detour route while a new span is built across the Salmon River.

“This isn’t your everyday job,” said Barry Peterson, operations manager for Harcon Inc.

The Spokane construction firm has worked on such projects as the Argonne Road underpass and the Oldtown bridge over the Pend Oreille River.

If Harcon and its subcontractor don’t get the U.S. 95 bridge moved and reopened in 78 hours, they’ll pay $625 for every additional 15 minutes.

The unusually high penalty reflects the state’s priority in keeping U.S. 95 open.

“This is the most important bridge in the state,” said Thomas Pfister, the Idaho Department of Transportation’s lead designer for the new Goff Bridge.

Nearly 2,000 vehicles per day use the bridge, about 330 of them commercial.

That number will likely go up when construction is completed in winter 1998. The new bridge will be wider, higher and longer, making it better able to handle trucks and big recreational vehicles.

The bridge is also known as the Time Zone Bridge because it sits near the dividing line between Mountain and Pacific times.

It will be closed just after midnight Thursday. That’s Pacific Time, said Ralph Poore, a public affairs specialist for the transportation department.

The demolition of concrete approaches to the bridge will take 12 to 18 hours, Poore said.

“Sometime after noon Friday, they’ll start jacking up the bridge to put roller plates under it,” he said. “They will move the bridge a little bit, check for any kind of settlement or shift, make sure everything is OK.

“About Saturday evening is when they should go for broke, starting to push the bridge to the new site. It’ll be inched over, moving about two feet every 15 minutes.”

Work will be stopped if winds exceed 20 mph.

High water has caused some problems for construction crews. Originally, the plan was to move the bridge in May. That would have avoided disrupting the prime business season for Riggins’ 12 river outfitters.

There were also delays caused by difficulty drilling holes in the riverbed for steel pillars that will support the old bridge.

As of Tuesday, all systems appeared to be “go” for the weekend project.

Still, Poore said, some department engineers were nervous about the unusual undertaking. “This is the kind of thing that makes and breaks careers.”

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MEMO: This sidebar appeared with the story: U.S. HIGHWAY 95 DETOUR Bridge construction will stop traffic on U.S. Highway 95 north of Riggins, Idaho, from 12:01 a.m. Friday to 6 a.m. Monday. Inland Northwest drivers traveling to southern Idaho will have to drive through Washington and Oregon. That route covers more miles and offers less scenery than Idaho’s mountainous midsection. But for many motorists it will take less time because they can travel at freeway speeds. A traveler headed from Coeur d’Alene to the National Oldtime Fiddlers Contest in Weiser will cover 390 miles taking the western detour. That compares with 347 miles on U.S. 95.