Table of Contents

Background

The preliminary interchange approval process is the first of several required approvals that may be needed as part of the project development process. This process is intended to be a planning-level assessment completed several years prior to construction. Its purpose is to demonstrate that the proposed project is consistent with the region’s long-range plans and that its location is generally suitable for an interchange based on general transportation planning principles.  

This approval process examines if the proposed location is suitable for an interchange based on consistency with local and regional plans, high-level needs, functional classification of the cross-street, proposed local roadway network and associated access management changes, and interchange spacing. It is not a direct test of benefits and costs, regional priority, or a determination that an interchange is the best solution. Years later, once the environmental process is complete, projects must demonstrate that they continue to show consistency with regional policy by completing a Metro Freeway Project Approval to the Metropolitan Council per MN Statute 473.166.

Preliminary interchange approval is needed before applying for several competitive funding programs including the Regional Solicitation, MnDOT’s Transportation Economic Development Program (TED), and MnDOT’s Highway Freight Program.

This approval process is based on work originally done in 1979 by a joint committee of the Transportation Advisory Board and the Met Council. It has been revised and simplified over time to reflect policy changes, revised state and federal laws and regulations, and experience with applying the criteria. The Met Council is committed to a future review of this approval process that includes regional stakeholders. The rationale for requiring this approval comes from the following Imagine 2050 Transportation Policy Plan (TPP) action:

• Action 1F. Maintain, review, and update, as needed, access management guidelines for principal arterial and minor arterial corridors to preserve and enhance their safety and capacity, as measured by person throughput. Identify opportunities to manage, consolidate, and limit access or repair street grids, as appropriate, when implementing roadway improvement projects. Coordinate with MnDOT and regional partners on access guidelines.

For this approval process, the term interchange will include traditional interchanges along with any other location with grade-separated crossing roadways and one or more adjacent access connections between the two roadways.

It is important to note that some types of interchange improvement projects must go through this approval process and other types do not. 

Types of interchange projects that need approval through this process:

• Addition (or removal) of an interchange on a principal or minor arterial

Types of interchanges projects that do not need approval through this process:

• Preservation, safety, or mobility investments not described above (for example new turn lanes or added through lanes)
• Modifications to the existing ramp(s), interchange design, or configuration not described above
• New local roadway connections to an interchange ramp or ramp terminal 

Evaluation Criteria

A proposer begins this review process by submitting materials addressing each of the evaluation criteria described below to the Interchange Planning Review Committee. The committee is comprised of staff from the Met Council and MnDOT Metro District. If proposed projects include the Interstate System, Federal Highway Administration staff will also participate. In cases where MnDOT Metro District is not the road authority, the relevant road authority is substituted (for example MnDOT District 3 in the urban part of Wright and Sherburne counties, and in some cases Anoka, Dakota, Ramsey or Scott counties or St. Paul). The relevant boundary is the federally recognized, designated planning boundary for the Metropolitan Planning Organization, which includes the counties of Anoka, Hennepin, Ramsey, Carver, Scott, Dakota and Washington, and the urban portion of Wright and Sherburne counties.

The committee will review the proposal for consistency with these criteria. In many cases a conversation between the proposer and the committee will be needed to reach a common understanding of how the proposal is or is not consistent with the region’s long-term plans. The review process is completed when the committee provides a letter of findings to the proposer. The approval process is intended to be a planning-level assessment and detailed traffic modeling and analysis is not required. 

1. Consistency with local and regional planning

Interchange access should be considered only when it supports local comprehensive plans approved by the Met Council, as well as Minnesota Go, Imagine 2050, and the Imagine 2050 Transportation Policy Plan.  

Imagine 2050 is the long-term development guide for the Twin Cities region. The shared goals for the region as well as the transportation specific objectives include:

• Our region is equitable and inclusive.
  • Historically disadvantaged communities are better connected to jobs, education, and other opportunities.
  • We repair and eliminate disparate and unjust impacts and harms to Black people, Indigenous people, and people of color.
  • We better meet the transportation needs of people who have disabilities or limited mobility.  
• Our communities are healthy and safe.
  • People do not die or face life-changing injuries when using any form of transportation.
  • People feel safer, more comfortable, and more welcome when using any form of transportation.
  • We mitigate and avoid harm to people caused by nearby transportation infrastructure and use (for example air quality, noise, light).
  • People are better connected to community and cultural resources that support their physical, emotional, and mental well-being.
  • People can increase physical activity with more opportunities to walk, roll, or bike.
• Our region is dynamic and resilient.
  • People and businesses trust that transportation infrastructure and services will withstand and recover quickly from natural and human-caused disruptions.
  • People can better meet their daily needs with timely, reliable, direct, and affordable options beyond driving alone.
  • People experience more predictable travel times without experiencing excessive delays when traveling on highways.
  • People and businesses can rely on predictable and cost-effective movement of freight and goods.
• We lead on addressing climate change.
  • The region’s transportation system minimizes its greenhouse gas emissions.
  • People have more reliable access to zero emissions vehicle infrastructure.
  • By 2050, the region reduces vehicle miles traveled by 20% per capita below 2019 levels.
• We protect and restore to natural systems.
  • The region’s transportation system protects, restores, and enhances natural systems (for example air, water, vegetation, and habitat quality). 

2. Project need

The need for an additional interchange or access at an existing location must be demonstrated and documented before consistency with the long-range plans can be found. The Intersection Mobility and Safety Study was completed in 2024 and prioritized at-grade intersections into three tiers (High Priority, Medium Priority, and Low Priority) by the magnitude of the problem at each intersection. The results of this regional study can help build a case for the project. Projects classified as High Priority have larger documented problems and a larger investment, such as an interchange, may be needed.

In most cases, new interchanges should be built in a logical sequence when they are a part of a conversion of an arterial to a freeway. If the long-term goal is not a freeway, then nontraditional designs should be considered to match the scale of the solution to the scale of the problem and to be consistent with plans for the corridor. With few exceptions, a new interchange should be within the Metropolitan Urban Service Area. 

3. Local roadway network and access management

Interchange access is not to be provided if the need is justified only for any of these reasons:

• As a convenience for short trips
• To compensate for lack of a planned adequate complementary minor arterial or collector system
• To compensate for deficient minor arterial or frontage road capacity  
• To correct collector or minor arterial capacity deficiencies caused by poor design or excessive access to adjacent parcels  

Regional travel demand for the principal arterial system will take precedence over local or land parcel development and related access needs.

When an interchange is proposed on an arterial, the project should, at a minimum, include the removal of all access within one-half a mile of the center of the proposed interchange and any at-grade full-access intersections within one mile along the free flow side of the interchange. It is recommended that access needs should be evaluated as part of an overall corridor plan or sub-area plan.

4. Interchange spacing

Interchanges should be spaced at a minimum of one mile apart (center to center) along a freeway. Interchanges spaced less than one mile apart will require justification and may require special design features such as auxiliary lanes to maintain safety and efficiency. If it is determined that it is appropriate to locate an interchange at less than one mile spacing or to modify an existing interchange with this deficiency, the safe operation of the main roadway must be maintained. Outside of the Metropolitan Urban Service Area, interchanges are typically not needed within two miles of each other along a freeway due to the lack of intense development.