Skip to main content

Noise Mitigation

What the Noise Mitigation Program is About

Noise is considered any unwanted sound, especially one that is loud or unpleasant and that causes disturbance. Highway traffic noise comes from three sources: the engine, the exhaust and the interaction between the tires and pavement. ODOT’s Noise Mitigation Program uses a standard modeling software to measure highway traffic noise for noise sensitive land uses to determine noise impacts. These impacts are then considered for noise mitigation in the form of noise barriers.

Importance of Noise Mitigation

The effects of noise on human health have been demonstrated in numerous studies. Reducing highway traffic noise for noise-sensitive land uses is an important facet in reducing these effects and increasing the quality of life for Oklahoma residents.

ODOT’s Noise Mitigation Program seeks to identify impacted noise-sensitive land uses and equitably provide noise mitigation measures for those that meet feasible and reasonable standards.

Frequently Asked Questions

A noise study is only done when a project qualifies as a Type I federal-aid project. This usually means the road is being widened to handle more traffic or moved to a new location. ODOT can’t do a noise study unless the project meets these criteria. You can find the full definition of a Type I project in the federal regulations under 23 CFR 772.

Noise walls will only be added to a project if it meets the ODOT Noise Policy's feasible and reasonable criteria.

There are two ways traffic noise can be an impact:

  • Too loud overall: If future noise levels are very close to or higher than limits set by the FHWA.
  • Big increase in noise: If the new traffic noise is 15 decibels louder than it used to be, even if it doesn’t go over the official limit.

Feasibility means: Can we build something to reduce noise, and will it work?

Examples:

  • Is there room to build a noise wall?
  • Can it reduce noise by at least 5 decibels?
  • Will it interfere with roads, driveways, or drainage?

Reasonableness means: Is it fair and affordable?

ODOT uses these rules to decide:

  1. Do the people living nearby want noise help?
  2. Can the wall reduce noise by 7 decibels for most of the closest homes?
  3. Will the cost stay under $30,000 per home helped?

The cost is based on how big and tall the wall needs to be. The tallest walls are usually no more than 22 feet high.

Only if it’s a very thick forest—at least:

  • 100 feet wide
  • 20 feet tall
  • Completely blocks the view

Since most roadside trees don’t meet these conditions, the FHWA doesn’t count trees as a way to reduce highway noise.

View the ODOT Noise Policy.

Visit the Federal Highway Administration for guidance on noise-compatible land use planning.