Kiewit Infrastructure South Co. will lead the construction of a $787.5-million replacement of the Interstate 55 bridge crossing the Mississippi River between Tennessee and Arkansas at Memphis.

The project, also dubbed America’s River Crossing, will replace the existing 75-year-old I-55 bridge to add capacity, improve safety standards, ensure route resiliency and maintain optimal operational conditions, according to the Tennessee Dept. of Transportation (TDOT). The Construction Manager/General Contractor agreement with Kiewit Infrastructure South is being finalized.

A shared effort of TDOT and the Arkansas Dept. of Transportation (ARDOT), the new bridge will be larger and designed to meet modern seismic codes, as it sits on the New Madrid fault line. 

Constructed before the U.S. Interstate system, the bridge was not built to Interstate standards, per TDOT and ARDOT, and due to its age and construction, seismic retrofits were determined to cost between $250 million and $500 million, classifying it as a non-candidate for that retrofitting. The existing bridge is approximately 5,222 ft-long, including approach spans, according to ARDOT. 

According to project information, the design of the cable-stayed bridge will be based on "displacement-based seismic design" philosophy, which seeks to assess the displacement capacity of a structure and its inherent hysteretic damping under a given loading. 

Using that approach, the bridge will be designed to remain undamaged and operational following a 1,000-year seismic event, and resist collapse with a 2,500-year seismic event. The design is expected to reduce seismic demand on bridge foundations by 25% or more. 

In October 2024, TDOT selected Parsons Transportation Group Inc. for engineering and design services. Design is underway on the project, set to start right-of-way acquisition later this year and begin construction in fiscal year 2026.

In a December 2023 application for the federal Bridge Investment Program, TDOT and the Arkansas Dept. of Transportation (ARDOT) list the estimated total cost of the project at $787.5 million, and a four-year construction period expected to wrap up in the third quarter of 2030. 

The project was awarded nearly $400 million from the Federal Highway Administration’s (FHWA) Bridge Investment Program, and the Tennessee and Arkansas departments of transportation each are committing up to $200 million toward the project, which marks the largest single transportation investment in state history for Tennessee, TDOT says. 

In its announcement of more than $5 billion in Bridge Investment Program awards, the FHWA says the project will receive $394 million as part of a round of grants “that will fund the reconstruction, repair and restoration—using American-made materials–of 12 nationally significant bridges.” 

The bridge will support the expected 64,000 vehicles that will cross the Mississippi River between Arkansas and Tennessee each day by 2050, TDOT says. Currently, more than 38,000 vehicles per day cross the bridge.