Archie Ingersoll, Published April 28 2014
ND has 7th-highest rate of structurally deficient bridges
That’s according to a new report from a construction industry group, the American Road & Transportation Builders Association, that says 16 percent of North Dakota’s 4,439 bridges are structurally compromised – the seventh-highest percentage among U.S. states.
The report, which relied on 2013 data from the U.S. Department of Transportation, singled out the 10 structurally deficient bridges in North Dakota that receive the most traffic. The one that sees the most daily crossings – 13,780 – is the West Fargo bridge that carries U.S. Highway 10 over the Sheyenne River.
The bridge, built in 1938, is slated to be replaced during the 2015 construction season. “It’s just met its life expectancy, and it just needs to be rebuilt to meet current and future traffic needs,” said Jamie Olson, a spokeswoman for the North Dakota Department of Transportation.
The tenth-most traveled North Dakota bridge on the list is also in Cass County – the North Dakota Highway 18 bridge over Interstate 94 near Casselton. That bridge, constructed in 1960, has 2,650 daily crossings.
Its problem is rooted in the surrounding soil, which is causing the abutment to move laterally, said state bridge engineer Terry Udland.
“It’s not a real big issue to us. We have a lot of the bridges of the Red River Valley that have the same issue, and that’s because of the soils,” he said.
Udland said there are no plans to replace or repair the bridge, which is being monitored through inspections.
“If it ever got to be anything significant, then we would have a rehabilitation project there,” he said.
The ARTBA report ranked Minnesota 35th overall, with 8 percent of its bridges labeled structurally deficient. Of those bridges, the 10 that see the most traffic are all in the Twin Cities area, except for one in the Duluth area, the report says.
In west-central Minnesota, six of the 341 bridges that the Minnesota Department of Transportation oversees are classified as structurally deficient, said Dan Kuhn, bridge engineer for District 4, which includes Moorhead and Detroit Lakes. He said those six bridges are set to be replaced by 2017.
Bridges in North Dakota and Minnesota are inspected at least every two years, and inspectors rate them on a scale of zero to 9. If a bridge’s substructure, superstructure or deck is rated 4 or less, the bridge is tagged as structurally deficient.
Udland emphasized that just because a bridge is deemed structurally deficient does not mean it’s unsafe.
“If the bridge isn’t safe, we’d close it,” he said. “In North Dakota, my experience has been if there’s an issue with one of our bridges, we take care of it.”
Udland said 2.9 percent of the bridges managed by the state are structurally deficient while a little over 18 percent of those controlled by counties have the same classification.
“We have a lot of bridges on the county system that probably only see a couple vehicles a day,” he said. “And the counties don’t have a really big interest in fixing those or replacing those.”
Cass County Engineer Jason Benson said that of the county’s 241 bridges that are 20 feet or longer, 50 are structurally deficient and eight are functionally obsolete, which means a bridge doesn’t meet current design standards. He said some of the county’s bridges are considered structurally deficient because they have load or width restrictions.
“We’ve got a lot of challenges with just the sheer quantity and the age of our structures,” Benson said, noting that about 40 percent of the county’s bridges will reach the end of their lifespans in the next 20 years.
Call for funding
ARTBA’s report was released along with a warning that the nation’s bridge situation could worsen unless Congress takes steps to replenish the Highway Trust Fund, which supports road, bridge and public transportation projects.
“Letting the Highway Trust Fund investment dry up would have a devastating impact on bridge repairs,” ARTBA’s chief economist, Alison Premo Black, said in a statement. “It would set back bridge improvements in every state for the next decade.”
Udland in North Dakota and Kuhn in Minnesota both said funding has not been a hurdle to repairing or replacing bridges in their respective states.
“If we’ve got a bridge that needs attention, we’ll make sure that we get it programmed whether it’s through state funding or federal participation,” Kuhn said.
Kuhn said that following the Interstate 35W bridge collapse in 2007, Minnesota officials put a special focus on bridge maintenance.
“That concerted effort did allow us extra funding to go after these bridges that have been on the deficiency-status list,” he said.
Readers can reach Forum reporter Archie Ingersoll at (701) 451-5734