Title 23 of the United States Code (Highways) authorizes funding of the federal highway system, and provides that standards for the construction of the highway system must be developed. Section 109 of the law requires that the Secretary of the Department of Transportation develop and promulgate standards for federal aid highway noise levels. The federal noise regulations for FHWA and for the Federal Transit Administration (FTA) are contained in 23 CFR 772, Procedures for Abatement of Highway Traffic and Construction Noise. The regulations state that “In order to obtain FHWA approval, the highway agency shall develop noise policies in conformance with this regulation and shall apply these policies uniformly and consistently statewide” (23 CFR 772.7), thus delegating regulation of federal-aid highway projects to the state transportation agencies. Vermont submitted their most recent noise policy, Noise Analysis and Abatement Policy, to FHWA in 2011.

Airport noise is regulated under Airport Noise Compatibility Planning (14 CFR 150) as well as FAA policy and guidance.

When It Is Required

The federal highway noise regulations and the Vermont noise policy apply to any highway project that requires FHWA approval or uses FHWA funding. Noise modeling is required for any Type I highway project, which is defined in 23 CFR 772.5 as “A proposed Federal or Federal-aid highway project for the construction of a highway on new location or the physical alteration of an existing highway which significantly changes either the horizontal or vertical alignment or increases the number of through-traffic lanes.”

Permit or Approval Process

There is no application or permit for regulating noise impacts. If noise impact analysis is required for transportation projects, it is typically conducted early in the design process as part of NEPA compliance. Depending on the level of NEPA documentation required, this may mean modeling of different alternatives to estimate the noise levels and determine the potential noise impacts from a project. When a proposed highway project has the potential for noise impacts, the Vermont noise policy requires the following:

It is VTrans policy that all analysis of traffic noise shall be conducted as described in 23 CFR 772.11. Noise analyses for Type I projects may be performed for sound levels within actual or proposed VTrans right-of-way (ROW) limits, adjacent to potentially sensitive receptors or at such locations, beyond actual or proposed VTrans ROW limits, in areas that exhibit frequent human use of the types shown in the Noise Abatement Criteria. In the case of permitted developments, analyses may be performed within VTrans ROW limits or at locations, based upon said development plans, expected to become potentially sensitive receptor sites.

Analyses shall be conducted using the latest TNM (currently TNM 2.5) predictive computer program. A potential noise impact is identified when projected future traffic sound levels approach or exceed the Noise Abatement Criteria or when projected future traffic sound levels substantially exceed existing sound levels. Existing noise levels and future design year noise levels must be analyzed for all build alternatives carried forward for detailed analysis in the NEPA document.

The date of public knowledge for a Federal or Federal-aid highway project shall be the date of a Programmatic Categorical Exclusion (PACE) determination, the date of approval of a Categorical Exclusion (CE), or the date of a Finding of No Significant Impact (FONSI), or Record of Decision (ROD) for the project. Thereafter VTrans will not be responsible for providing noise analysis or abatement for any development subsequently permitted in proximity to the approved VTrans project.

Analysis of traffic noise shall occur for Type I projects only. VTrans does not have a program for Type II projects and noise analysis is not required for Type III projects.

Noise abatement will be considered for Type I projects only. When potential noise impacts are identified on such projects, VTrans will consider and evaluate noise abatement measures and make determinations regarding their feasibility and reasonableness. Feasibility determinations shall be based on acoustical, physical, and engineering factors, such as physical or topographical constraints; constructability; safety; maintenance; and technical constraints. Reasonableness shall be based on social, economic, and environmental factors, such as the ability to achieve a substantial noise reduction (7 dB for at least 25 percent of receptors); the number of receptors that will benefit; cost; and the perspectives of the benefitted receptors.

Table 1 is reproduced from Vermont’s Noise Policy and is used to determine if proposed noise levels constitute an impact. Leq and L10 are methods for measuring sustained sound levels.

Table 1 – Noise Abatement Criteria [Hourly A–

Weighted Sound Level Decibels (dBA)1]







Evaluation Location

Activity description





Lands on which serenity and quiet are of extraordinary significance and serve an important public need and where the preservation of those qualities is essential if the area is to continue to serve its intended purpose.










Active sport areas, amphitheaters, auditoriums, campgrounds, cemeteries, day care centers, hospitals, libraries, medical facilities, parks, picnic areas, places of worship, playgrounds, public meeting rooms, public or nonprofit institutional structures, radio studios, recording studios, recreation areas, Section 4(f) sites, schools, television studios, trails, and trail crossings.





Auditoriums, day care centers, hospitals, libraries, medical facilities, places of worship, public meeting rooms, public or nonprofit institutional structures, radio studies, recording studios, schools, and television studios.





Hotels, motels, offices, restaurants/bars, and other developed lands, properties, or activities not included in A-D or F.




Agriculture, airports, bus yards, emergency services, industrial, logging, maintenance facilities, manufacturing, mining, rail yards, retail facilities, shipyards, utilities (water resources, water treatment, electrical), and warehousing.




Undeveloped lands that are not permitted..


1. Either Leq (h) or L10 (h) (but not both) may be used on a project.

2. The Leq(h) and L10(h) Activity Criteria values are for impact determination only, and are not design standards for noise abatement measures.

3. Includes undeveloped lands permitted for this activity category.

Related Regulations

Regulatory programs with overlapping jurisdiction with Highway Noise regulations include, but are not necessarily limited to, the following:

Airport Noise and Compatibility Planning (14 CFR 150)

For More Information

The lead federal agency (FHWA, FAA, etc.) usually oversees and reviews noise studies. Contact the VTrans Environmental Section for correct procedures and contacts.

Highway Traffic Noise: Analysis and Abatement Guidance

VTrans Noise Analysis and Abatement Policy