Minnesota Department of Transportation

511 Travel Info

I-94

Between East St. Paul and Woodbury

Orange barrels on a highway

More about noise barriers

How does MnDOT determine whether a noise barrier is needed?

A noise barrier must be both feasible and reasonable if it is to be constructed with a highway project. The reasonability of a noisewall is determined by factors such as cost, amount of reduction in noise, safety, and site features. Decisions on noise mitigation locations are determined on a case-by-case bases.

Why does MnDOT conduct noise studies?

MnDOT conducts noise studies to assess existing noise levels and predict future noise levels. If noise impacts are identified MnDOT is required by federal law to consider noise mitigation.

How do noise barriers work?

Noise barriers block the direct path of sound waves from the highway to homes and businesses along the highway. They do not eliminate noise, they only reduce the noise. To be considered effective, a noise barrier must reduce noise impact to receptors by at least 5 decibels.

Can noise increase as it passes over the barrier?

No. Noise does not increase as it passes over the barrier. The further noise travels, the greater the reduction in noise.

Will trees be planted for aesthetics?

We will develop a landscaping program for the project following construction. The landscaping process usually begins 1-2 years following the completion of construction. On previous projects, MnDOT has involved communities in the landscaping process.

What impacts do noise barriers have on property values?

There haven't been any studies that link property values to noise barriers. Future buyers may either appreciate the noise reduction the barrier provides, or they may have aesthetic concerns about its presence.