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St. Anthony Falls (35W) Bridge
Encyclopedia
The I-35W Saint Anthony Falls Bridge crosses the Mississippi River
in Minneapolis
, Minnesota
in the U.S.
, carrying north–south traffic on Interstate Highway 35W
. The ten-lane bridge is the replacement for the I-35W Mississippi River Bridge, which collapsed on August 1, 2007. It was planned and is maintained by the Minnesota Department of Transportation
(Mn/DOT). The planning, design, and construction processes were completed faster than normal because Interstate 35W is a critical artery for commuters and truck
freight. The bridge opened September 18, 2008, well ahead of the original goal of December 24.
During the evening rush hour
at 6:05 pm on August 1, 2007, the main spans of the I-35W Mississippi River Bridge in Minneapolis
collapsed and fell into the river and onto its banks. The bridge was built in 1967, and was expected to carry 66,000 vehicles per day. Though intended to last fifty years, it collapsed after forty.
Originally, the bridge was striped for two lanes in each direction. In 1988, the four shoulders were converted to traffic lanes, accommodating four lanes in each direction. This allowed an increase in traffic flow. By 2004, an estimated 141,000 vehicles crossed the bridge each day.
Within hours of the previous bridge's demise, politicians pledged to rebuild the bridge at an accelerated pace. Federal transportation officials pledged US$
5 million for the cleanup and recovery. U.S. Representative
Jim Oberstar
, who represented Minnesota's 8th congressional district
and chaired the House Transportation Committee
, introduced an earmark
to direct a minimum of $250 million to help replace the bridge; the bill passed the House unanimously on August 3 as Republican
Senator Norm Coleman
and Democratic-Farmer-Labor
(DFL) Senator Amy Klobuchar
introduced companion legislation in the Senate. President
George W. Bush
signed the legislation on August 6, 2007, after visiting the site on August 4. After months of wrangling with Congress over spending proposals, President Bush
signed the spending bill that included funding for the bridge on December 26, 2007.
Mayor R. T. Rybak
(DFL) said that future needs and policy considerations shouldn't be ignored in the rush to build a replacement and sought a new bridge able to handle increased traffic as well as mass transit. Meetings between state transportation officials (Mn/DOT), Rybak, State Transportation Commissioner Carol Molnau
, and Governor Tim Pawlenty
yielded a desire to build a 10 lane bridge that will last 100 years, with the possibility of bus rapid transit or light rail
lines. Rybak said, "Transit needs to play some role in this or otherwise we would need to build a much wider bridge in the future." At a public forum in Roseville
, hundreds of Twin Cities residents participated in a discussion about the bridge design. The overriding theme of the crowd was a desire to plan for the bridge's use of mass transit. Commissioner Molnau, in conjunction with Metropolitan Council
Chairman Peter Bell, recommended that light rail not be incorporated in the new bridge design. But Pawlenty, responding to constituents and the mayor, directed Mn/DOT to design the bridge to be light rail-ready. He said the estimated additional $20 to $35 million would be paid for by the state.
After the collapse of the bridge's predecessor, Mn/DOT announced to potential contractors that they should express their intention to bid on the project by August 8, 2007. A typical bridge project of this scale in Minnesota
would be expected to take three years to complete, but state transportation officials hoped to open this replacement bridge in 15 months by using a design/build contract that allowed design and construction of the bridge to proceed concurrently. Mn/DOT announced on August 9 that five companies/consortia
had been approved to bid on the project and requested that the bids be submitted by September 18, 2007.
Despite criticism and a lawsuit that alleged that theirs was not the best proposal, Flatiron Constructors, Inc. and Manson Construction Company were awarded the contract on September 19, 2007; Flatiron's was the highest-priced and longest schedule of the bids submitted. The lead designer was Figg Engineering, with Ayres Associates providing hydraulic and scour analyses. TKDA of Saint Paul was the engineer of record for the approach highways, second street bridges, retaining walls, lighting, and water resource engineering services on the project. While the total cost was expected to be between USD $300 million and $350 million for the 1,900-foot (579 m) multi-span bridge, including financial incentives for accelerating the schedule, the winning bid was for USD $234 million. Disincentives for missing the completion date of December 24, 2008 included a $200,000 per day penalty, while incentives to finish early could have been as much as $27 million.
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MnDOT maintained a project page that tracked all activities associated with the construction of the bridge including weekly updates, traffic impacts, construction photos, animations, and virtual walk tours. On December 17, 2007, the first slab of concrete, 200 feet (61 m) long, 13.5 feet (4.1 m) wide, and 4.5 feet (1.4 m) thick, was poured off-site, which began to shape the bridge. Pilings sunk 100 feet (30.5 m) into the earth support the ends of the bridge, which contains 50000 cubic yards (38,227.7 m³) of concrete.
The bridge construction progressed more quickly than expected. Construction work was performed in shifts with as many as 400 workers during the day, and 200 at night. On April 8, 2008 Mn/DOT announced the half way point of construction had been reached, and predicted that completion might be ahead of schedule by as much as three months.
This prediction was borne out by events, as the Minnesota Department of Transportation opened the bridge to traffic at 5:00 in the morning on September 18, 2008. Minnesota State Patrol
cars at both the north and south ends allowed rush hour traffic to build up behind them. Once the construction barricades were removed at 5:00 am the First Responders, State Troopers, and Mn/DOT trucks slowly crossed the bridge with rush hour traffic in tow, officially opening the bridge. Flatiron-Manson is expected to earn $27 million in bonuses for accelerated performance.
personnel. The bridge is illuminated with light-emitting diodes (LEDs). Although LED lighting is not generally approved for such highways, this bridge roadway illumination is a test project. The bridge also incorporates multichromatic decorative lighting, which is used to illuminate the structure at night.
The bridge was a finalist in the 2009 America's Transportation Awards for "representing the best in innovative management, accountability and timeliness".
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...
in Minneapolis
Minneapolis, Minnesota
Minneapolis , nicknamed "City of Lakes" and the "Mill City," is the county seat of Hennepin County, the largest city in the U.S. state of Minnesota, and the 48th largest in the United States...
, 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...
in the U.S.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, carrying north–south traffic on Interstate Highway 35W
Interstate 35W (Minnesota)
Interstate 35W , is an Interstate Highway in the U.S. state of Minnesota, passing through downtown Minneapolis. It is one of two through routes for Interstate 35 through the Twin Cities of Minneapolis and Saint Paul, the other being Interstate 35E through downtown Saint Paul...
. The ten-lane bridge is the replacement for the I-35W Mississippi River Bridge, which collapsed on August 1, 2007. It was planned and is maintained by the Minnesota Department of Transportation
Minnesota Department of Transportation
The Minnesota Department of Transportation oversees transportation by land, water, and air in the U.S. state of Minnesota. The cabinet-level agency is responsible for maintaining the state's trunk highway system The Minnesota Department of Transportation (Mn/DOT, pronounced "min-dot") oversees...
(Mn/DOT). The planning, design, and construction processes were completed faster than normal because Interstate 35W is a critical artery for commuters and truck
Truck
A truck or lorry is a motor vehicle designed to transport cargo. Trucks vary greatly in size, power, and configuration, with the smallest being mechanically similar to an automobile...
freight. The bridge opened September 18, 2008, well ahead of the original goal of December 24.
Collapse of the previous bridge
During the evening rush hour
Rush hour
A rush hour or peak hour is a part of the day during which traffic congestion on roads and crowding on public transport is at its highest. Normally, this happens twice a day—once in the morning and once in the evening, the times during when the most people commute...
at 6:05 pm on August 1, 2007, the main spans of the I-35W Mississippi River Bridge in Minneapolis
Minneapolis, Minnesota
Minneapolis , nicknamed "City of Lakes" and the "Mill City," is the county seat of Hennepin County, the largest city in the U.S. state of Minnesota, and the 48th largest in the United States...
collapsed and fell into the river and onto its banks. The bridge was built in 1967, and was expected to carry 66,000 vehicles per day. Though intended to last fifty years, it collapsed after forty.
Originally, the bridge was striped for two lanes in each direction. In 1988, the four shoulders were converted to traffic lanes, accommodating four lanes in each direction. This allowed an increase in traffic flow. By 2004, an estimated 141,000 vehicles crossed the bridge each day.
Funding
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....
5 million for the cleanup and recovery. U.S. Representative
United States House of Representatives
The United States House of Representatives is one of the two Houses of the United States Congress, the bicameral legislature which also includes the Senate.The composition and powers of the House are established in Article One of the Constitution...
Jim Oberstar
Jim Oberstar
James Louis "Jim" Oberstar is a former U.S. Representative who served in the U.S. Congress from 1975 until 2011 as a member of the Minnesota Democratic–Farmer–Labor Party. He represented northeastern , which included the cities of Duluth, Brainerd, Grand Rapids, International Falls, and Hibbing...
, who represented Minnesota's 8th congressional district
Minnesota's 8th congressional district
Minnesota's 8th congressional district covers the northeastern part of Minnesota. It is anchored by Duluth, Minnesota which is the fourth largest city in state. It also includes most of the Mesabi and Vermilion iron ranges. The district is best-known for its mining, agriculture, tourism, and...
and chaired the House Transportation Committee
United States House Committee on Transportation and Infrastructure
The U.S. House Committee on Transportation and Infrastructure is a standing committee of the United States House of Representatives. John Mica currently chairs the committee.-History:...
, introduced an earmark
Earmark (politics)
In United States politics, an earmark is a legislative provision that directs approved funds to be spent on specific projects, or that directs specific exemptions from taxes or mandated fees...
to direct a minimum of $250 million to help replace the bridge; the bill passed the House unanimously on August 3 as Republican
Republican Party (United States)
The Republican Party is one of the two major contemporary political parties in the United States, along with the Democratic Party. Founded by anti-slavery expansion activists in 1854, it is often called the GOP . The party's platform generally reflects American conservatism in the U.S...
Senator Norm Coleman
Norm Coleman
Norman Bertram Coleman, Jr. is an American attorney and politician. He was a United States senator from Minnesota from 2003 to 2009. Coleman was elected in 2002 and served in the 108th, 109th, and 110th Congresses. Before becoming a senator, he was mayor of Saint Paul, Minnesota, from 1994 to 2002...
and Democratic-Farmer-Labor
Minnesota Democratic-Farmer-Labor Party
The Minnesota Democratic–Farmer–Labor Party is a major political party in the state of Minnesota and the state affiliate of the Democratic Party. It was created on April 15, 1944, with the merger of the Minnesota Democratic Party and the Farmer–Labor Party...
(DFL) Senator Amy Klobuchar
Amy Klobuchar
Amy Jean Klobuchar is the senior United States Senator from Minnesota. She is a member of the Minnesota Democratic-Farmer-Labor Party, an affiliate of the Democratic Party...
introduced companion legislation in the Senate. President
President of the United States
The President of the United States of America is the head of state and head of government of the United States. The president leads the executive branch of the federal government and is the commander-in-chief of the United States Armed Forces....
George W. Bush
George W. Bush
George Walker Bush is an American politician who served as the 43rd President of the United States, from 2001 to 2009. Before that, he was the 46th Governor of Texas, having served from 1995 to 2000....
signed the legislation on August 6, 2007, after visiting the site on August 4. After months of wrangling with Congress over spending proposals, President Bush
George W. Bush
George Walker Bush is an American politician who served as the 43rd President of the United States, from 2001 to 2009. Before that, he was the 46th Governor of Texas, having served from 1995 to 2000....
signed the spending bill that included funding for the bridge on December 26, 2007.
Design debate
MinneapolisMinneapolis, Minnesota
Minneapolis , nicknamed "City of Lakes" and the "Mill City," is the county seat of Hennepin County, the largest city in the U.S. state of Minnesota, and the 48th largest in the United States...
Mayor R. T. Rybak
R. T. Rybak
Raymond Thomas Rybak, Jr. , known as R. T. Rybak, is the 46th and current mayor of the city of Minneapolis, Minnesota. In the 2001 election Rybak defeated incumbent Sharon Sayles Belton by a margin of 65% to 35%; the widest margin in city history for a challenge to an incumbent...
(DFL) said that future needs and policy considerations shouldn't be ignored in the rush to build a replacement and sought a new bridge able to handle increased traffic as well as mass transit. Meetings between state transportation officials (Mn/DOT), Rybak, State Transportation Commissioner Carol Molnau
Carol Molnau
Carol Molnau was the 46th Lieutenant Governor of Minnesota. She formerly served as head of the Minnesota Department of Transportation...
, and Governor Tim Pawlenty
Tim Pawlenty
Timothy James "Tim" Pawlenty , also known affectionately among supporters as T-Paw, is an American politician who served as the 39th Governor of Minnesota . He was a Republican candidate for President of the United States in the 2012 election from May to August 2011...
yielded a desire to build a 10 lane bridge that will last 100 years, with the possibility of bus rapid transit or light rail
Light rail
Light rail or light rail transit is a form of urban rail public transportation that generally has a lower capacity and lower speed than heavy rail and metro systems, but higher capacity and higher speed than traditional street-running tram systems...
lines. Rybak said, "Transit needs to play some role in this or otherwise we would need to build a much wider bridge in the future." At a public forum in Roseville
Roseville, Minnesota
As of the census of 2000, there were 33,690 people, 14,598 households, and 8,598 families residing in the city. The population density was 2,543.9 people per square mile . There were 14,917 housing units at an average density of 1,126.4 per square mile...
, hundreds of Twin Cities residents participated in a discussion about the bridge design. The overriding theme of the crowd was a desire to plan for the bridge's use of mass transit. Commissioner Molnau, in conjunction with Metropolitan Council
Metropolitan Council
The Metropolitan Council or Met Council is the regional governmental agency and metropolitan planning organization in Minnesota serving the Twin Cities seven-county metropolitan area. The Met Council is granted regional authority powers in state statutes by the Minnesota Legislature. These powers...
Chairman Peter Bell, recommended that light rail not be incorporated in the new bridge design. But Pawlenty, responding to constituents and the mayor, directed Mn/DOT to design the bridge to be light rail-ready. He said the estimated additional $20 to $35 million would be paid for by the state.
Award of contract
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...
would be expected to take three years to complete, but state transportation officials hoped to open this replacement bridge in 15 months by using a design/build contract that allowed design and construction of the bridge to proceed concurrently. Mn/DOT announced on August 9 that five companies/consortia
Consortium
A consortium is an association of two or more individuals, companies, organizations or governments with the objective of participating in a common activity or pooling their resources for achieving a common goal....
had been approved to bid on the project and requested that the bids be submitted by September 18, 2007.
Despite criticism and a lawsuit that alleged that theirs was not the best proposal, Flatiron Constructors, Inc. and Manson Construction Company were awarded the contract on September 19, 2007; Flatiron's was the highest-priced and longest schedule of the bids submitted. The lead designer was Figg Engineering, with Ayres Associates providing hydraulic and scour analyses. TKDA of Saint Paul was the engineer of record for the approach highways, second street bridges, retaining walls, lighting, and water resource engineering services on the project. While the total cost was expected to be between USD $300 million and $350 million for the 1,900-foot (579 m) multi-span bridge, including financial incentives for accelerating the schedule, the winning bid was for USD $234 million. Disincentives for missing the completion date of December 24, 2008 included a $200,000 per day penalty, while incentives to finish early could have been as much as $27 million.
Construction
The bridge construction progressed more quickly than expected. Construction work was performed in shifts with as many as 400 workers during the day, and 200 at night. On April 8, 2008 Mn/DOT announced the half way point of construction had been reached, and predicted that completion might be ahead of schedule by as much as three months.
This prediction was borne out by events, as the Minnesota Department of Transportation opened the bridge to traffic at 5:00 in the morning on September 18, 2008. Minnesota State Patrol
Minnesota State Patrol
The Minnesota State Patrol is the statewide police force in the state of Minnesota. The State Patrol concentrates primarily on traffic enforcement and highway safety. Troopers are also involved with accident reconstruction and commercial vehicle enforcement. The State Patrol capitol security...
cars at both the north and south ends allowed rush hour traffic to build up behind them. Once the construction barricades were removed at 5:00 am the First Responders, State Troopers, and Mn/DOT trucks slowly crossed the bridge with rush hour traffic in tow, officially opening the bridge. Flatiron-Manson is expected to earn $27 million in bonuses for accelerated performance.
Technology
The bridge is equipped with anti-icing sprayers and was constructed with high-strength concrete. There are 323 sensors that regularly measure bridge conditions such as deck movement, stress, and temperature. The data will be compiled and analyzed by University of MinnesotaUniversity of Minnesota
The University of Minnesota, Twin Cities is a public research university located in Minneapolis and St. Paul, Minnesota, United States. It is the oldest and largest part of the University of Minnesota system and has the fourth-largest main campus student body in the United States, with 52,557...
personnel. The bridge is illuminated with light-emitting diodes (LEDs). Although LED lighting is not generally approved for such highways, this bridge roadway illumination is a test project. The bridge also incorporates multichromatic decorative lighting, which is used to illuminate the structure at night.
Awards
The bridge has been named a project of the year by the American Public Works Association. The association awards are presented annually to recognize excellence in public works projects.The bridge was a finalist in the 2009 America's Transportation Awards for "representing the best in innovative management, accountability and timeliness".
Further reading
- Patrick Nunnally, ed. The City, the River, The Bridge: Before and After the Minneapolis Bridge Collapse (University of Minnesota Press; 2011) 183 pages; studies by civil engineers, geographers, and others on the events and aftermath of the collapse of the bridge in August 2007.
External links
- I35W St. Anthony Falls Bridge - Minnesota Dept. of Transportation - Official DOT Site for the Replacement Bridge. Shows Artist Renderings of the new bridge.
- Stribcam, Minneapolis Star-Tribune. Retrieved on 2008-05-08. Live webcam of bridge under construction.