Milton-Madison Bridge (US 421)

The Milton-Madison Bridge connects Milton, Kentucky to Madison, Indiana and carries US 421 over the Ohio River. The historic two-lane Cantilever is currently being replaced.

The two communities had been connected with a ferry but both had envisioned a fixed crossing that would provide a more reliable operation.1 After much persisting, the J.G. White Engineering Company agreed to design the bridge in 1928 to be operated as a tolled facility through the National Toll Bridge Company. Financing was sourced from Commonwealth of Kentucky Bridge Revenue Bonds, authorized by the Murphy Act of 1928.8 The construction company chosen was the Mount Vernon Bridge Company.4

The original Milton-Madison Bridge was opened to traffic on December 20, 1929 at a cost of $1,365,101.84.1 8 The bridge consisted of a 5% approach grade, 19 spans and five separate bridge design types.4

  • Span 1 – 3: Deck trusses measuring 148 feet and 3 inches, 149 feet and 3.75 inches and 149 feet and 3.75 inches.
  • Span 4: Pratt through truss measuring 149 feet and 9.75 inches.
  • River span 1 between pier 5 and 6: Cantilever truss measuring 253 feet and 11.25 inches.
  • River span 2 between pier 6 and 7: Cantilever truss measuring 727 feet and 3 inches.
  • River span 3 between pier 7 and 8: Cantilever truss measuring 600 feet.
  • River span 4 between pier 8 and 9: Cantilever truss measuring 599 feet and 6 inches.
  • Span 12: Through girder with two exterior girders.
  • Span 13 – 19: Multigirder spans.

The new bridge featured a 45 cent toll for automobile drivers and a 5 cent toll for pedestrians.1 Maintenance was completed by the state Department of Highways with costs being paid out by the Road Fund and tolls were used to pay down the bonds. The Milton-Madison Bridge connected Kentucky State Routes 36, 37 and 42 with Indiana Highways 7, 29, 56 and 62.8

Between December 10, 1937 and August 31, 1947, 2,079,810 automobiles crossed the span.8 On November 1, 1947,8 the toll was removed for the bridge and ownership of the span was transferred to the Kentucky Highway Department.1 The tolls were removed several years earlier than anticipated.8 Maintenance included paintings in 1950, 1957, 1966, 1976, 1984 and in 1997.4

In 1997, the bridge received a thorough rehabilitation.4 The project included the replacement of the bridge deck, structural steel repairs, patching on existing concrete elements and a new paint overlay. Prior to the rehabilitation, the bridge required a weight restriction, which was removed after the work was completed.

In a 2006 fracture critical inspection, the bridge was given a rating of 4, or poor condition, on both main truss members and floor beams. While all of the truss members were adequate for Kentucky truck permit loadings, the crossing featured inventory ratings less than Inventory Loading (HS20).4 Issues included pack rust in numerous areas and pitting and section loss to truss members, exterior stringers and floor beams and lateral bracing members. The paint was also rated as fair, and was tarting to fail in several areas due to prior corrosion and poor adhesion. The deck was rated in good condition, although deck leaking was causing some stringers to rust beneath.

An estimated lifespan for the bridge without another rehabilitation was set at ten years.7 The span at the time of the inspection carried 10,700 vehicles per day.


In June 2008, the Kentucky Transportation Cabinet (KYTC) and the Indiana Department of Transportation (INDOT) launched the Milton-Madison Bridge Project in an effort to replace the aging bridge.1 The first public meetings were held that fall.

The projected cost of the new bridge was $131 million, and it was expected that both states would identify state and federal funding sources for the cost of the project.3 The cost of the new bridge would be split evenly between the states.

In February 2010, the bridge project received final federal environmental approval,3 and shortly after the project received a boost when the project was awarded $20 million in funding from the American Reinvestment and Recovery Act.6 A project contract was advertised that June,3 and on September 23,5 the construction contract was awarded to Walsh Construction with a low bid of $103.9 million, or 20% below the original estimate. The highest bid submitted was $136.2 million.5 Walsh’s bid was the only one submitted that had a total closure time of the bridge of less than one year.6 The company partnered with Burgess & Niple Engineers of Columbus, Ohio and Buckland and Taylor, Ltd. of North Vancover, British Columbia.3 6 Ground was broken on November 30 for the new Milton-Madison Bridge.5 9

Construction began in January 2011 with the first phase of the project, which involved strengthening the existing piers.2 3 Work on temporary approach ramps from Kentucky State Route 36 and Vaughn Drive began in the summer, which allowed for the existing approach ramps to be removed and replaced.

Milton-Madison Bridge (US 421)

During that time, work began on the temporary downstream piers, and construction of the first truss for the new bridge for the downstream piers began in the fall.2 The 600-foot, 1,700-ton section of truss was preassembled, and was floated upstream where several hydraulic jacks lifted the entire section into place onto temporary piers. A second truss, 727-foot long, was constructed and lifted into place onto the temporary piers. The remaining components for the truss was constructed on top of the temporary piers using conventional cranes.

Traffic was rerouted onto the new bridge via temporary ramps in April 2012,12 and on June 3, 2013, vehicles were switched to the new trusses,11 12 allowing for the removal of the bridge decks on the old spans. On July 23, a 600-foot span over the main navigational channel was demolished with small explosive charges from Advanced Explosives Demolition.10

The use of temporary piers and ramps will lead to a total bridge closure time of less than ten days, less than an earlier projected closure date of one year.6 As such, ferries that were going to be deployed during the construction project will not be needed.

The new bridge, which will include a pedestrian sidewalk and bike lanes, is expected to open by September 15, 2013.6

  • Gallery
  • Statistics
  • Further Reading
  • Sources


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  • Designation: US 421
  • Crosses: Ohio River
  • Bridge Type: Cantilevered truss
  • Total Length: 3,181 feet and 6.375 inches
  • Main Span Length: 727.3 feet
  • Deck Width: 20.75 feet
  • Height: ~100 feet


  • Designation: US 421
  • Crosses: Ohio River
  • Total Length: 2,426 feet
  • Main Span Length: 727.3 feet
  1. “Bridge History.” Milton-Madison Bridge Project. Michael Baker Jr., n.d. Web. 20 Jan. 2012. Article.
  2. “Construction.” Milton-Madison Bridge Project. Michael Baker Jr., n.d. Web. 20 Jan. 2012. Article.
  3. “Schedule & Funding.” Milton-Madison Bridge Project. Michael Baker Jr., n.d. Web. 20 Jan. 2012. Article.
  4. Existing Bridge Deficiencies White Paper. N.p.: Michael Baker Jr, 2008. Milton-Madison Bridge Project. Milton-Madison Bridge Project. Web. 20 Jan. 2012. Article.
  5. “Groundbreaking planned on new Ohio River bridge linking Madison, Indiana and Milton, Kentucky.”Associated Press 24 Sept. 2010: n. pag. Courier-Journal. Web. 20 Jan. 2012. Article.
  6. Weidenbener, Lesley Stedman. “Madison bridge to close only 10 days during reconstruction.” Courier-Journal [Louisville] 28 Sept. 2010: n. pag. Courier-Journal. Web. 20 Jan. 2012. Article.
  7. Hecox, Doug. “USDOT Gives Green Light on Milton-Madison Bridge Replacement.” Federal Highway Administration. United States Department of Transportation, 17 June 2010. Web. 23 Jan. 2012. Article.
  8. The Story of the Splendid Milton-Madison Bridge. N.p.: n.p., 1947. N. pag. Northern Kentucky Views. Web. 23 Jan. 2012. Article.
  9. LaHood, Ray. “Milton-Madison Bridge connects more than just two sides of the Ohio River.” Fast Lane. U.S. Department of Transportation, 30 Nov. 2010. Web. 23 Jan. 2012. Article.
  10. “Old Milton-Madison Bridge set to be demolished.” Milton-Madison Bridge Project. Michael Baker Jr., n.d. Web. 25 July 2013. Article.
  11. “Traffic switches to new bridge next week.” Madison Courier 29 May 2013: n. pag. Madison Courier. Web. 25 July 2013. Article.
  12. Shields, Evan. “Bridge One Step Closer To Completion.” Madison Courier 3 June 2013: n. pag. Madison Courier. Web. 25 July 2013. Article.


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