Of North Dakota's 4,355 bridges, 10.8 percent have been deemed "structurally deficient," according to a report from a national trade organization.
That's the 10th-highest percentage in the country, according to the report issued by the American Road and Transportation Builders Association.
The structurally deficient designation means one of a bridge's key elements is in poor condition. Across the nation, four in 10 bridges need to be repaired or replaced, according to the ARTBA report.
Though North Dakota's proportion of deficient bridges is higher compared to other states, the number actually declined from 512 bridges in 2014, the report stated. ARTBA estimated it would cost $243.6 million to repair all of North Dakota's structurally deficient bridges.
Officials from the North Dakota Department of Transportation noted the data cited in the ARTBA report isn't the most current. For instance, the report cites the Kennedy Bridge in Grand Forks as structurally deficient, but in November, NDDOT completed a multi-year rehab of the bridge. That included a pier replacement, along with a new coat of paint and aesthetic lighting.
"The way the data is put in, it's going to be somewhat aged," NDDOT bridge engineer Jon Ketterling said of the ARTBA report. "They're going to highlight bridges that have probably been rehabbed or replaced, or there are plans to do it in the near future."
There were three Grand Forks County bridges listed on ARTBA's report, including the Kennedy. The other two: a U.S. Highway 2 bridge over the Saltwater Coulee and a small Interstate 29 bridge about 4 miles south of Manvel. The department plans to replace the Saltwater Coulee bridge "over the next couple of years," said Nancy Huether, NDDOT's structure management engineer.
As for the other bridges on the ARTBA list, NDDOT officials say many are low-volume structures on county roadways. The department is responsible for maintaining bridges on the state system; counties are responsible for maintaining their own roadways, according to Ketterling.
In total, NDDOT is responsible for approximately 1,100 bridges in the state. Ketterling maintained that NDDOT "has an effective bridge preservation, rehabilitation and replacement program in which bridge inspection, maintenance, rehabilitation and replacement are a major component of the transportation system."
What's more, the structurally deficient designation doesn't necessarily mean a bridge is unsafe, Ketterling noted. The designation simply means a key element of the bridge has "a condition that warrants attention," he said.
When it comes to planning for future bridge repairs, the department uses bridge management software to help with decision-making, Ketterling said. Every two years, the NDDOT also inspects bridges in the state, including those it's not responsible for maintaining.
"Even though we are not responsible for maintaining the county bridges, we are responsible for inspecting them," Huether said. "So if they are unsafe, we have the ability to recommend closure for those structures."
NDDOT spends roughly $25 million annually to rehab and replace bridges, according to Ketterling.
Bridges to the east
Meanwhile, 5 percent of Minnesota's more than 13,358 bridges were deemed structurally deficient, according to the ARTBA report. That equates to 668 bridges, down from 802 in 2014,
the report stated. The percentage of deficient bridges in Minnesota ranks 38th in the country, according to ARTBA.
Minnesota's estimated bridge repair needs total about $243.6 million, the report stated.
For its part, the Minnesota Department of Transportation has a "pretty robust maintenance program" for bridges, said Paul Konickson, bridge engineer for District 2, which encompasses Polk County.
"One thing Minnesota does that not all states do is we do have dedicated staff for each district," he said. "So we routinely do certain maintenance tasks to help get longevity out of our bridges and keep them in service longer in a better condition."
For instance, the department regularly flushes streets with water after winter to clear them of any road salt build-up. The salt can be corrosive to bridges and other structures, according to Konickson.
In addition, MnDOT often performs bridge inspections at least twice a year, as opposed to just once. Each year, MnDOT typically targets about $100 million worth of bridge replacement and rehab projects, Konickson said.
The ARTBA report didn't call out any bridges in Clay or Polk counties, save the Kennedy Bridge, which has already undergone rehab work. Most of the bridges on the Minnesota list were in Hennepin County, home to Minneapolis.