Prior to construction, some of the structures along the I-64 corridor were more than 60 years old.  The original roadway and bridges were built in sections from the late 1930s through the early 1960s. They were in desperate need of replacement.

There are approximately 30 bridges on or over I-64 within the project corridor.  New bridges are initially given a rating of a 9. As bridges age and deteriorate, this rating goes down. Before the project began, half of the bridges within the project corridor were rated 4 or 3. Bridges at level 2 must be closed.

Replacing these bridges now and grouping them in with adjacent improvements was the major reason for doing this project. Otherwise, the bridges would have to have been left as-is; bridge replacements would have to be done as independent projects and corridor-wide traffic improvements could not have been made.

MoDOT officially launched The New I-64 project in 2000. MoDOT used the findings of the 1997 Major Transportation Investment Study (MTIA), conducted by the East-West Gateway Council of Governments (EWGCOG), as the starting point for the study phase. 

• The MTIA report identified transportation problems along I-64 and I-170 and pinpointed concerns related to neighborhood impacts, funding, safety and security, air quality and noise.
• The resulting MTIA included the broad recommendations to reconstruct I-64, along with proposed means of improving specific interchanges along the route. The East-West Gateway Board approved the study recommendations in 1997 which included the location of future MetroLink alignments, including the Shrewsbury Line that opened in August 2006, the reconstruction of I-64's pavement and bridges, improvement to the I-64 interchanges, the addition of one lane each direction from I-270 to I-170 (not east of I-170) and not extending I-170 south of I-64.
• The results of this study were used by East-West Gateway to program the federal transportation funding for the I-64 project.

In July 2005, the New I-64 project received its funded budget of $535 million from EWGCOG.  Also during that month, an Environmental Impact Statement was completed with the issuance of a Record of Decision from the Federal Highway Administration.