Minnesota Department of Transportation

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Project development

Environmental process | Environmental review

Noise Analysis


The purpose of this process is to provide open, two-way communication in regards to the noise process between the project team and the community in which the project is located.

When to use this subject

Federal projects

If the project is a Federal Highway Administration (FHWA) undertaking (e.g. FHWA obligation authority (funding) or an FHWA approval action is required), determine if this project meets any of the Type I definition criteria. If the project involves any of the criteria below, the entire project area in the environmental document is Type 1. Contact the appropriate personnel for assistance with the Type I determination and further guidance.

Type 1 Definition Criteria:

  1. Construction of a highway on a new location
  2. Physical alteration of an existing highway where there is either:
    • Substantial horizontal alteration
    • Substantial vertical alteration
  3. Bridge replacement that satisfies item 2 above
  4. Addition of a through-traffic lane(s) (including the addition of a through-traffic lane that functions as a highway occupancy vehicle (HOV) lane, contraflow lane, high occupancy toll (HOT) lane, bus lane, or truck climbing lane)
  5. Addition of an auxiliary lane, unless that auxiliary lane is a turn lane
  6. Addition or relocation of interchange lanes or ramps to complete an existing partial interchange
  7. Restriping of existing pavement for the purpose of adding a through traffic lane or auxiliary lane
  8. Addition of a new or substantial alteration of a weigh station, rest stop, ride share lot, or toll plaza

Transit only projects

Base your determination to use FHWA’s or the Federal Transit Authority’s (FTA) noise analysis and procedures on the specific circumstances of the project. The FHWA noise regulations under 23 CFR §772 apply to multimodal projects even though the regulation does not define the term “multimodal.” A proposed transit project that will share existing highway right of way is not necessarily a multimodal project under 23 CFR §772.7 (a). A transit only project is a project that is not a multimodal project for the purposes of 23 CFR §772.7 (a) and meets all of the following three criteria:

  1. FTA is the lead agency in the NEPA process and FHWA is not a co-lead. The FHWA’s limited participation is as a cooperating agency
  2. The main transportation purpose of the project, as the Purpose and Need statement in the NEPA document will state, is transit-related and not highway-related
  3. There are no federal aid highway funds on the project

Use the FTA’s Transit Noise and Vibration Impact Assessment Guidance Manual procedures to evaluate noise impacts for the transit and highway elements of transit only projects that meet all three of these criteria.

State projects

You do not need a noise analysis for state-only funded projects (that are not FHWA undertakings) unless the project crosses mandatory Environmental Quality Board (EQB) thresholds for highway projects (Minnesota Rules, part 4410.4300, subpart 22) or if there is a voluntary EAW for a project on the trunk highway system.

Construction noise

You must consider construction noise on all projects and discuss if sensitive receptors are in close proximity. See 2017 MnDOT Noise Requirements Section 6.0 Construction Noise and Sample construction noise write up for environmental documents, construction impacts for guidance.

Community noise engagement

If you are completing a noise analysis, you must have a community noise engagement process as part of the overall public engagement process for your project. See the Community Noise Engagement document for more information. Information about the noise barrier voting process is provided in MnDOT Noise Requirements for MnDOT and other Type I Federal-aid Projects.

You must consult with FHWA, Office of Environmental Stewardship, or Office of State Aid for Local Transportation for all classes of action. For specific process information, see the process and other guidance pages and/or contact the individual on the contacts page.

How this subject fits into the overall project development process

Begin working on community noise engagement  at the start of environmental process (typically after a consultant is hired). You may need to work on the process throughout the life of the project.

Organizations involved