Dakota County Intersection Evaluation

Development Type: None

Services Provided: Intersection Evaluation

Client: Dakota County and City of Burnsville

We are currently in the midst of a project evaluating three intersections for Dakota County in partnership with the City of Burnsville. As originally conceived, this type of project was a simple traffic signal replacement, with the potential for an evaluation of the approach lane needs. With more options available than ever to control intersection traffic both safely and efficiently, the goal of this project shifted to determining the most appropriate type of control for today and into the future.

Within the universe of alternatives for traffic control exists options for traditional, non-traditional, access management, and grade separated solutions. We approached this project in the following manner:

  • Initial review of intersection characteristics, daily volumes, and surrounding area to narrow this universe of alternatives. For instance, grade-separated or other alternatives that involved elevated approaches or lanes (bridges) were quickly ruled out as too expensive.
  • Determination of issues/concerns, which involved a detailed examination of existing operations, future projects and operations with the existing signal, safety/crash history and crash rates, and review of other factors (adjacent bus stops, bicycle/pedestrian treatments, etc.) that could impact operations.
  • Analysis of feasible intersection options, which included operations, safety, bicycle/pedestrian impacts, and several other measurements of effectiveness categories.

For one intersection, we considered what we came to call our “Hybrid” option. This option restricted left turn and through movements from one side of the intersection and removed the existing traffic signal. The image below shows this Hybrid design.

This design tried to accomplish several items – removing a legacy traffic signal is not fully justified by warrants or intersection volumes, maintaining full movements to and from the neighborhood to the east of the intersection, and restricting movements on the west side of the intersection that have easy access to the north for those movements.

Unfortunately, this option does not satisfy all our objectives for the intersection. For instance, poor operations are expected for the westbound left turn movement during peak periods (a major change from today’s more than acceptable operations). A future retail development is also possible on the west side of the intersection which would desire full access.

We don’t have the final answer yet on what this intersection will be. However, by fully considering the existing and future issues along with the objective analyses of options (both conventional and alternative), we know we will make the best selection to meet the goals of the project and provide safe and efficient operations for all users.