The concept for improving transportation in the southeast portion of the Des Moines metropolitan area began in early 1970 and was referenced in the following transportation studies:

• November 1984 — Year 2020 Street and Highway Plan for the Des Moines Urbanized Area
• July 1994 — Revised Initial 1990 Des Moines Urbanized Area Transportation Plan
• October 1994 — Horizon Year 2020 Transportation Development Report

The Southeast Diagonal Corridor Study— Project Location and Major Investment Study was a preliminary location study conducted in 1999 by the City of Des Moines. An Environmental Impact Study (EIS) and Record of Decision (ROD) for the proposed alignment were completed between 2005 and 2010.

The SE Connector is the follow-up project to this study, construction of segments began in 2007.