Hamilton County takes early step to replace traffic signal at 146th, Hazel Dell with grade-separated roundabout


Hamilton County has taken an early step to redesign one of its most congested and dangerous intersections.

The Hamilton County Council recently approved $800,000 and Hamilton County commissioners approved a contract for design work at 146th Street and Hazel Dell Parkway, an intersection bordered by Carmel to the south and Noblesville to the north. Conceptual drawings — which are not final — for the intersection show 146th Street raised above a roundabout on Hazel Dell Parkway with on and off ramps to connect the roads.

“The intent right now is to move forward into the engineering of (the intersection) and at least get to 45 percent (completion of) plans and through the environmental review,” said Bradley Davis, highway director for the Hamilton County Highway Dept. “The environmental review could cause some changes to the concept.”

Improving the intersection has long been a priority for Hamilton County officials, as quick growth in the area led to the intersection hitting 20-year traffic projections within eight years, according to Hamilton County Commissioner Mark Heirbrandt. And safety has been a concern, too, with the Indianapolis Metropolitan Planning Organization ranking it among the top 50 most dangerous intersections in a 2016 study.

Davis said he estimates construction of the project to cost $30 million, and a funding source is yet to be identified. Heirbrandt said the county is seeking grants and sources of federal funding to help cover the cost.

“I wish we could (build) it sooner, but everything always comes down to money,” Heirbrandt said. “So, it’s our job to try to get any type of funding that might be available to be less burdensome on any of the taxpayers in the county.”

Because funding has not been secured, it is unclear when construction could begin.

Ultimately, county officials want to replace traffic signals along the 146th Street corridor with grade-separated roundabout intersections that would function much like those along Keystone Parkway in Carmel.

Design work is under way to transform the intersection of 146th Street and Allisonville Road near the border of Fishers, Carmel and Noblesville. Construction on the $29 million project is expected to begin in the spring of 2023 and be complete in the fall of 2024.