August 17, 2007

Missouri river bridges - are they safe?

ith the recent collapse of the I-35W bridge between Minneapolis and St. Paul over the Mississippi River, many people are wondering - are the current bridges that span the Missouri River safe?

According to the top engineer with the Nebraska Department of Roads, the answer is yes, even though three of the 17 bridges that allow traffic to cross over the river are considered to be in "poor" condition.

Six bridges actually have lower federal sufficiency ratings than the Twin Cities bridge but many other factors go into considering a bridge structurally unsafe. The U.S. Department of Transportation provides sufficiency ratings through their National Bridge Inventory and uses the numbers mainly to alert officials to begin repair or replacement planning. These numbers are also used as benchmarks to qualify for federal funding.

The six Missouri River bridges in Nebraska with rankings below 50 (which is the most recent rating given to the Twin Cities bridge) are Rulo (48.6), Plattsmouth (22.9), Bellevue (49.5), Veterans Memorial / South Omaha bridge (42.2), Decatur (49.3) and Yankton (47.5).

Rulo, Plattsmouth and Yankton bridges had condition ratings of "poor" in at least one of three

	Plattsmouth Bridge

criteria: deck, superstructure and substructure. Inspectors gave the lowest rating to the Plattsmouth toll bridge which is scheduled to be repaired next summer.

The Rulo truss bridge which was built in 1939 has been recently redecked. It was added to the National Register of Historic Places in 1993 and was featured in the movie Paper Moon. 

	Rulo Bridge

A new Yankton bridge is currently under construction. The estimated completion date is sometime in 2009.

A truss bridge that crosses the river at Brownville, NE was labeled "functionally obsolete" in 2006. It was built in 1939 and is now on the National Register of Historic Places. The term "functionally obsolete" refers mainly to matters such as width or lack of modern design standards.

The Bellevue toll bridge has been the subject of controversy for many years. It was built in 1950

	Bellevue Bridge

by the Bellevue Bridge Commission at a cost of $2.8 million. When the initial bonds were paid off in 2000, no one wanted to own it because of the cost it will take to make repairs. The Bridge Commission is currently attempting to secure $1 million in bonds for the repair work.

	South Omaha Bridge

Although listed on the National Register of Historic Places in 1992, the Veterans Memorial Bridge (originally called the South Omaha Bridge) is scheduled to be torn down and replaced with a new four lane girder bridge. Opening of the new bridge is expected to be in 2010. In the meantime, Nebraska has placed a 5-ton vehicle limit on the bridge.

The Decatur bridge, which officially opened in 1956, was built on dry land in 1951. The Missouri River was eventually rerouted to flow under the bridge. There are no former plans in place to make repairs to this bridge.

Over 70,000 bridges across the country are rated structurally deficient, however, of the 10 worst counties for bridges in the nation, seven are in Oklahoma and Nebraska.

Nebraska Department of Roads does have a policy of inspecting the Missouri River bridges every two years so we should all feel confident that the recent tragedy in the Twin Cities will not happen here.