Eden Avenue and Grange Road Roundabouts

Challenge

The City of Edina in Hennepin County, Minnesota, identified the Eden Avenue and Grange Road intersection, near City Hall and Highway 100, as a priority for improvement. The skewed layout caused frequent traffic delays and created safety risks for pedestrians crossing long distances without adequate facilities.

With substantial residential and commercial growth planned nearby, the outdated intersection design couldn’t support future traffic demands. To address this, officials proposed a mini-roundabout to improve traffic flow, align the intersection, lower vehicle speeds, and provide safer pedestrian access.

Solution

The City of Edina collaborated with SEH to transform the complex channelized right turn and four-way stop intersection into two three-legged intersections with dual mini-roundabouts. This approach achieved several critical objectives, enhancing traffic flow and safety for vehicles and pedestrians. The multifaceted process required careful planning, stakeholder collaboration, and a focus on sustainability to ensure a successful outcome. 

Traffic Flow and Safety Improvements

The Grandview East Area traffic project began with a study of planned developments and roadway upgrades within the area bounded by 50th Street, Eden Avenue, and Veron Avenue, primarily focusing on the Grange Road and Eden Avenue intersection.

The team evaluated two roundabout designs to improve traffic flow and safety with minimal land use. Initially, a dual roundabout, which is two closely connected roundabouts, was considered to facilitate smooth traffic transitions. However, further analysis favored a split intersection with two mini-roundabouts, each handling traffic from specific directions to reduce accident risk and optimize space. Mini-roundabouts allow continuous, one-way traffic around a central island, reducing congestion in limited spaces with moderate traffic volumes.

This new setup reduced conflict points from 32 in the previous all-way stop design to 14, allowing faster, smoother traffic flow, reduced vehicle speeds, and improved overall efficiency.

Pedestrian safety features included:

• Wide sidewalks
• Shorter crossing distances
• Median refuge islands
• Plans for future pedestrian flashers to protect walkers and cyclists

Sustainability and Environmental Concerns

Sustainability was an essential component of the project design as the team developed the stormwater management plan based on federal, state, and local requirements.  Stormwater management techniques were implemented to protect the environment, with soil amendments used to increase infiltration capacity. These efforts maintained existing peak flow rates and volumes discharging into the MnDOT-owned trunk line, preventing strain on the system during rainfall events. This approach displayed the commitment to minimizing environmental impact while delivering a functional and efficient roadway design.

There were also environmental considerations with the security modifications at the Police Department. Specifically, the parking lot construction included modifications that created an additional 425 sq. ft. of new impervious area. To mitigate the additional impervious area, soils within existing green spaces next to Grange Hall were amended to increase infiltration capacity. 

Efficient Project Delivery

With the construction of an adjacent development underway, SEH was tasked by City staff to complete the design and construction before the development's opening. The team proactively coordinated with key stakeholders, including the City of Edina, MnDOT, local developers, and utility companies, to efficiently manage tasks like temporary ramp closures and traffic detours. The project was delivered on schedule through precise planning and close collaboration, maintaining smooth progress and minimizing disruptions.

Additionally, alternate routes to Highway 100 were coordinated so that the Edina Police Department could maintain response times during construction.

Community Benefits

Pedestrians, cyclists, and drivers now enjoy smoother traffic flow and fewer delays in their daily commutes. The design also prepares the City for future growth, enabling it to accommodate increased traffic and new developments seamlessly.

The Eden Avenue and Grange Road Roundabouts project exemplifies how collaboration, innovation, and thoughtful design can address immediate traffic concerns while ensuring safety, sustainability, and lasting community benefits that support future growth.