In the early 1990s, the Main Street portion of the Triangle project was included as part of the Hilliard Rome Road Widening Project. Hilliard Rome Road and Main Street were to be widened from their existing 2 and 3-lane width to a full 5-lane width with curb and gutter, an underground drainage system, street lighting, and pedestrian facilities.

In the late 1990s, the City of Hilliard began planning for a minor improvement in the Triangle area outside the limits of the Hilliard Rome Road project. However, extensive traffic modeling conducted in 2000/2001, as part of the City's Thoroughfare Plan, identified the need for more major improvements in the Triangle area to accommodate growth in and around Hilliard to the west, and to provide more capacity in an east/west direction along the Scioto Darby Road/Cemetery Road corridor, linking the growth areas to the interchange of Cemetery Road and I-270.

In 2001, a traffic feasibility study was conducted for the Triangle project. As part of this study, several alternatives were evaluated, including:

• Conversion of Cemetery Road and Scioto Darby Road to one-way pairs
  
• Closure of Scioto Darby Road between Donatos and Hilliard United Methodist Church
  
• Other similar traditional alternatives that included a system of traffic signals or stop-controlled intersections
  

From this study, several alternatives were eliminated from consideration due to poor operations or safety. The selected alternative known as the "Signalized Alternative" was developed. This alternative removed the traffic signal at Main Street/Scioto Darby Road, made significant turning movement restrictions at this intersection, emphasized the Cemetery Road corridor, and utilized High School Drive to route through traffic that previously used the Scioto Darby/Main Street intersection. Design of this alternative commenced in 2001 and as of 2003 those plans were approximately 70 percent complete.

In 2004, Hilliard City Council requested that the use of Modern Roundabouts be evaluated for the Triangle area. A Modern Roundabout Feasibility Study commenced in the spring of 2004. Using traffic information from the 2001 Triangle Study, two two-lane modern roundabouts at the intersections of Main Street/Cemetery Road and Main Street/Scioto Darby Road were shown to provide an excellent level of service. The findings of the Modern Roundabout Feasibility Study were presented to Hilliard City Council in September 2004.

A public meeting was conducted in December 2004 presenting the two feasible alternatives (Signalized Alternative and Modern Roundabout Alternative). Based on the comments received from the public and from feedback received through the Hilliard Chamber of Commerce, the City determined that it was appropriate to pursue the Modern Roundabout Alternative.

In March 2005, the City requested statements of qualifications from several prequalified engineering consultants to perform detailed analyses and provide detailed design services for these intersection improvements. In May 2005, the City of Hilliard selected the engineering firm Burgess & Niple, Inc. based on their qualifications.

Updated traffic analyses were completed by Burgess & Niple confirming that a solution involving roundabouts at the Main Street intersections of both Cemetery Road and Scioto Darby Road is the most desirable in terms of traffic flow, property access, and safety. A public meeting was held in March 2006 upon completion of the preliminary roundabout design. Based on comments received during this public meeting and the findings of the engineering analysis, the City of Hilliard made the decision to continue with the roundabout design. Final design is complete, funding has been secured through a combination of an Ohio Public Works Commission grant/loan and local funds, and construction is underway.