I-90 Mississippi River Bridge
Encyclopedia
The I-90 Mississippi River Bridge is a plate girder bridge
Plate girder bridge
A plate girder bridge is a bridge supported by two or more plate girders. The plate girders are typically I-beams made up from separate structural steel plates , which are welded or, in older bridges, bolted or riveted together to form the vertical web and horizontal flanges of the beam...

 that connects La Crosse
La Crosse, Wisconsin
La Crosse is a city in and the county seat of La Crosse County, Wisconsin, United States. The city lies alongside the Mississippi River.The 2011 Census Bureau estimates the city had a population of 52,485...

, Wisconsin
Wisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...

 to rural Winona County
Winona County, Minnesota
As of the census of 2000, there were 49,985 people, 18,744 households, and 11,696 families residing in the county. The population density was 80 people per square mile . There were 19,551 housing units at an average density of 31 per square mile...

, Minnesota
Minnesota
Minnesota is a U.S. state located in the Midwestern United States. The twelfth largest state of the U.S., it is the twenty-first most populous, with 5.3 million residents. Minnesota was carved out of the eastern half of the Minnesota Territory and admitted to the Union as the thirty-second state...

. It is an automobile bridge that traverses the Mississippi River
Mississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

, and is part of the Interstate 90
Interstate 90
Interstate 90 is the longest Interstate Highway in the United States at . It is the northernmost coast-to-coast interstate, and parallels US 20 for the most part. Its western terminus is in Seattle, at Edgar Martinez Drive S. near Safeco Field and CenturyLink Field, and its eastern terminus is in...

 route. The railing consists of solid concrete; the steel structure is painted a dark green. There is another automobile crossing a few miles south of this bridge; the Mississippi River Bridge, a combination of two bridges, along with the La Crosse West Channel Bridge
La Crosse West Channel Bridge
The La Crosse West Channel Bridge is a plate girder bridge that spans the west channel of the Mississippi River between Barron Island in Wisconsin, and La Crescent, MN. Together with the Mississippi River Bridge it forms a connection between La Crescent and downtown La Crosse, Wisconsin.-See...

 connect La Crescent, Minnesota
La Crescent, Minnesota
As of the census of 2000, there were 4,923 people, 1,940 households, and 1,367 families residing in the city. The population density was 1,634.4 people per square mile . There were 2,014 housing units at an average density of 668.6 per square mile...

 and La Crosse, Wisconsin
La Crosse, Wisconsin
La Crosse is a city in and the county seat of La Crosse County, Wisconsin, United States. The city lies alongside the Mississippi River.The 2011 Census Bureau estimates the city had a population of 52,485...

.

Potential rehabilitation or replacement

Although the current bridge has no weight restrictions and operates at an acceptable level of service, there are number of problems with the bridge and surrounding roadways:
  • The deck is deteriorating, the most pressing issue in the short term.
  • The bridge is of an obsolete, non-redundant structural design similar to that of the Hoan Bridge
    Hoan Bridge
    The Daniel Hoan Memorial Bridge is a tied arch bridge that connects Interstate 794 in downtown Milwaukee, Wisconsin, to the Lake Freeway across the Milwaukee River inlet...

     in Milwaukee, Wisconsin
    Milwaukee, Wisconsin
    Milwaukee is the largest city in the U.S. state of Wisconsin, the 28th most populous city in the United States and 39th most populous region in the United States. It is the county seat of Milwaukee County and is located on the southwestern shore of Lake Michigan. According to 2010 census data, the...

    , which suffered a substantial structural failure. After the Hoan Bridge incident, the I-90 Mississippi River Bridge was hurriedly inspected and found to be in satisfactory condition, but concern about the basic steel structural design remains.
  • A lack of standard shoulders inhibits emergency responses to incidents on the bridge and does not provide enough room for disabled vehicles to get out the traffic lanes.
  • There are issues with the interchange on the Minnesota side, including a curve on the main travel lanes that is sharper than desirable for an interstate, a confusing design, and congestion on some of the ramps.
  • There are capacity problems at the Dresbach Rest Area on the Minnesota side, which currently has only limited room for expansion. Compounding the problem, it is currently accessible from the eastbound direction, even though it is intended for westbound traffic only.
  • There are no provisions for bicyclists and pedestrians on the bridge.


In 2006, Mn/DOT commissioned a study on ways to rectify some or all of these issues. Some of the options that were presented included:
  • Replacing the deck only, estimated cost $23 million
  • Widening and rebuilding the existing structure with either additional piers or strengthening the foundation, estimated cost $40–$58 million
  • Building a new westbound girder bridge
    Girder bridge
    A girder bridge, in general, is a bridge built of girders placed on bridge abutments and foundation piers. In turn, a bridge deck is built on top of the girders in order to carry traffic. There are several different subtypes of girder bridges:...

     and converting the existing bridge to eastbound only, estimated cost $63 million
  • Building a new girder bridge
    Girder bridge
    A girder bridge, in general, is a bridge built of girders placed on bridge abutments and foundation piers. In turn, a bridge deck is built on top of the girders in order to carry traffic. There are several different subtypes of girder bridges:...

    , extradosed bridge
    Extradosed bridge
    An extradosed bridge employs a structure that is frequently described as a cross between a girder bridge and a cable-stayed bridge. The name comes from the French word extradossé, which is derived from the word extrados. Extrados is defined as the exterior curve of an arch.This description is...

    , or cable stayed bridge, and demolishing the existing one, estimated cost $59–$71 million


Selecting a preferred alternative will take further studies, but the least costly option that would address the non-redundant design of the existing bridge is $58 million, while the least costly total replacement option is $59 million. There are also a number of concepts for rebuilding the interchange on the Minnesota side, depending on whether the bridge is rebuilt or replaced. Complicating construction will be the proximity to steep bluffs and an active railway on the Minnesota side, proximity to the La Crosse Municipal Airport
La Crosse Municipal Airport
-Top Destinations:-Unusual History:The La Crosse Airport can accommodate the world's largest aircraft in service today. One of the world's largest passenger jumbo jets, the Boeing 747 Air Force One , has made overnight trips to this airport with every U.S...

, which could limit the height of any towers, and barge traffic, which restricts where piers may be placed. Construction is currently planned for 2013.
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