Bridge weight limits to send heavy loads on long detour.

Byline: Randi Bjornstad The Register-Guard

Starting in less than three weeks, the extra-heavy, oversized trucks that now rumble up and down Interstate 5 through the Eugene-Springfield area will begin detouring to local roads to avoid deteriorating bridges crossing the McKenzie and Willamette rivers.

The bypass could go on for years as the state struggles to find money to fix aging freeway bridges.

After decades of wear and tear, the bridge at milepost 198 at Armitage Park over the McKenzie and the bridge at 192 south of the metro area over the Willamette no longer can take the stress of superheavy loads, the Oregon Department of Transportation says.

The concrete box girders that support the bridges have sustained stress fractures that "worsen exponentially with use by extra-heavy vehicles," said Don Ehrich, ODOT manager for the Eugene-Springfield area.

"We have no choice but to limit the weight on them" - starting March 5, Ehrich said. "There's no immediate threat from passenger vehicles or standard trucks, but we will continue to monitor the condition of these bridges regularly."

Although built to state-of-the-art specifications at the time, both bridges "suffer from the choice of design," which includes seismic deficiencies as well as outmoded building materials, Ehrich said. The double bridge over the McKenzie dates to 1959 and the span across the Willamette followed in 1962.

"The Willamette bridge was scheduled for earthquake upgrading several years ago, but that project kept getting delayed, and now it's obvious that spending a couple million on that doesn't make sense if the whole bridge needs to be rebuilt," he said.

Until the girders can be repaired or more likely replaced - at a price tag that could range as high as $50 million for each bridge - trucks and cargo that weigh more than 105,500 pounds no longer can travel through the Eugene-Springfield area on I-5.

The restrictions won't affect most truck traffic, including triple trailer loads. But most oversized loads that require escort vehicles, including trucks transporting logging or heavy construction equipment, will have to detour.

Some smaller loads could be affected based on the number of axles on a trailer and the weight of the freight, because distribution of weight determines wear and tear on roads.

Diverting from both directions

To make the detour, southbound loads will leave I-5 at the Corvallis-Lebanon exit at Milepost 228. They will travel west on Highway 34 to Corvallis, then south on Highway 99 West through Monroe and Junction City to Belt Line Road in Eugene. From there, trucks will travel east and link up with Highway 126, then head up the McKenzie River to Highway 97 in Central Oregon before continuing south.

Coming from the south, oversized trucks will go east on Highway 58, through Oakridge to Highway 97, and then on to the north.

ODOT officials estimate that the total number of diverted trucks per day could be as many as 300. But most will turn eastward either at Portland or Salem.

"Most of the (oversized) traffic that ends up here will be vehicles with destinations in this area, so it would have been coming here anyway," Ehrich said.

But he acknowledged that the detours amount to a suggestion, not a law, so truckers who don't want to drive hundreds of miles out of their way can try to find shorter, albeit more circuitous routes as long as their loads don't exceed legal weight, height or width limits for state or local roadways.

Impacting trucking industry

Long-haul truckers already have been coping with detours and load limits in the state for several years, and the impact on the industry has been substantial, said Bob Russell, president of the Portland-based Oregon Trucking Association.

"For 18 months, heavy-haul traffic - mostly the really big loads like logging equipment and big Caterpillars - has been off I-5 because of the rebuilding of the Ford's Bridge down by Roseburg," Russell said. "But this new detour makes things much worse." The cost to operate a truck pulling a "regular" load amounts to about $1 per mile, Russell said. Running an oversize load costs at least double that amount, and the bridge detours already exceed 300 miles.

"The biggest problem will be to get to places south of there, like Roseburg, because truckers will have to take Highway 126 east all the way to Highway 97 and then come all the way back on Highway 58 to get where they need to go," he said.

Nonetheless, he shares Ehrich's belief that the nuisance of having oversized trucks on state highways in the local area won't bother Lane County residents much.

Taryl Perry, executive director of the Chamber of Commerce in Junction City, which lies on the detour route, hopes they're right.

"We do get quite a few large trucks coming through town as it is - log trucks, delivery trucks, gas and farm trucks - so we're pretty used to that kind of traffic," Perry said. "I'm more concerned that the state already has plans to redo Highway 99 through town this summer. Those two things together could make things worse."

HOW FREIGHT TRAVELS IN OREGON

Trucks: 250 tons annually; 67 percent of total

Railroad: 63 million tons; 17 percent

Ship: 56 million tons; 15 percent

Airplane: 3.7 million tons; 1 percent

- Oregon Department of Transportation

CAPTION(S):

INSIDE Oregon's bridges, with an average age of 40 years, have been wearing out. State officials estimate that it would cost $4.7 billion to repair or replace them all - and the cost is going up / A5 Please turn to BRIDGES, Page A5 Bridges: The concrete girders need work Continued from Page A1