THE PROJECT
The deteriorating 83-year-old Milton-Madison Bridge, carries US 421 across the Ohio River connecting the historic towns of Madison, Ind., and Milton, Ky.
After a year of environmental studies and input from community, state and federal agencies, KYTC and INDOT determined that a method called “superstructure replacement” offered the fastest and most cost-effective way to build a safe new bridge, while having the least impact on the historic towns and the natural environment. Superstructure replacement involves building a new steel truss atop the existing piers, which will be brought up to modern standards.
Due to the use of innovative bidding, design and construction methods, the bridge is expected to close for a total of only 10 days during construction, rather than the anticipated year-long closure.
Using a construction method called “truss sliding,” a new 2,427-foot-long truss will be moved along steel rails and plates and “slide” into place atop the existing piers, which will be rehabilitated. (Click here to view a similar truss sliding bridge project.) The new span is expected to be open to traffic in 2013, making it the fastest modern-day bridge built across the Ohio River.
The first bridge closure took place April 25-28, 2012. The next bridge closure is expected just before the new bridge opens in 2013 after the new truss bridge “slides” from the temporary piers onto the rehabbed existing piers.
Two large preassembled sections of the new bridge were lifted onto temporary piers in June and September of 2012. Work on the truss is complete. Next steps include pouring the concrete bridge deck this spring.
