Of 72 Minnesota bridges identified as "fracture critical" after the Interstate 35W bridge collapsed in Minneapolis in 2007, nine have been replaced and another 11 are scheduled for replacement by 2018.
Bridge safety jumped back into the news this week when an Interstate 5 bridge over the Skagit River in Washington state collapsed, injuring several motorists.
The fatal I-35W collapse raised questions about inefficient and inadequate bridge inspections.
Nancy Daubenberger, state bridge engineer for the Minnesota Department of Transportation, said the state inspected all 4,500 bridges in the state highway system. In a report to the Legislature this year, the department said nine of the bridges with the most serious problems, including the DeSoto Bridge in St. Cloud, have been replaced.
Those bridges were considered fracture critical, meaning that if one load-bearing component failed, the entire bridge could.
The 11 that are scheduled to be replaced by 2018 include the Lafayette Bridge in St. Paul and the Hastings Bridge.
The rest of the 72 fracture critical bridges aren't ready for replacement now, but at least 10 more will be in about 15 years.
MnDOT has about 50 more bridge inspectors today than it did in 2007.
Money earmarked for the bridge program -- $2.5 billion in state, federal and bond money -- will run out in 2018.
"We have a quite an era of bridges that were built during the interstate era, a generation of bridges that were built then that are going to be coming due ... so a major investment in bridges will be needed at that time as well," Daubenberger said.
MnDOT officials estimate that the department will need just under $5 billion for bridges from 2018 to 2033.