Skip to Content


Procedures for Abatement of Highway Traffic Noise and Construction Noise

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble


Federal Highway Administration (FHWA), DOT.


Final rule.


This final rule amends the FHWA regulation that specifies the traffic noise prediction method to be used in highway traffic noise analyses. The final rule requires the use of the FHWA Traffic Noise Model (FHWA TNM) or any other model determined by the FHWA to be consistent with the methodology of the FHWA TNM. It also updates the specific reference to acceptable highway traffic noise prediction methodology and removes references to a noise measurement report and vehicle noise emission levels that no longer need to be included in the regulation. Finally, it makes four ministerial corrections to the section on Federal participation.


Effective Date(s): May 2, 2005. The incorporation by reference of the publication listed in this rule is approved by the Director of the Federal Register as of May 2, 2005.

Start Further Info


Mr. Mark Ferroni, Office of Natural and Human Environment, HEPN, (202) 366-3233, or Mr. Robert Black, Office of the Chief Counsel, HCC-30, (202) 366-1359, Federal Highway Administration, 400 Seventh Street, SW., Washington, DC 20590.

End Further Info End Preamble Start Supplemental Information


Electronic Access

This document and all comments received by the U.S. DOT Docket Facility, Room PL-401, may be viewed Start Printed Page 16708through the Docket Management System (DMS) at The DMS is available 24 hours each day, 365 days each year. Electronic submission and retrieval help and guidelines are available under the help section of this Web site.

An electronic copy of this document may be downloaded by using a computer, modem and suitable communications software from the Government Printing Office's Electronic Bulletin Board Service at (202) 512-1661. Internet users may also reach the Office of the Federal Register's home page at:​ and the Government Printing Office's Web page at:​nara.


The FHWA noise regulations (23 CFR 772) were developed as a result of the Federal-Aid Highway Act of 1970 (Pub. L. 91-605, 84 Sat. 1713) and applied to Federal-aid highway construction projects. This regulation requires a State DOT to determine if there will be traffic noise impacts in areas adjacent to federally-aided highways when a project is proposed for the construction of a highway on a new location or the reconstruction of an existing highway to either significantly change the horizontal or vertical alignment or increase the number of through-traffic lanes.

Analysts must use a highway traffic noise prediction model to calculate future traffic noise levels and determine traffic noise impacts. The FHWA developed its first prediction model described in “FHWA Highway Traffic Noise Prediction Model” (Report No. FHWA-RD-77-108), December 1978.[1]

To incorporate over two decades of improvements in predicting highway traffic noise,as well as continued advancements in computer technology, the FHWA, with assistance from the Volpe National Transportation Systems Center in Cambridge, Massachusetts(Volpe Center) developed a new state of the art highway traffic noise prediction model in 1998, “FHWA Traffic Noise Model,” Version 1.0 (FHWA TNM).[2] This model bases its calculations on totally new acoustical prediction algorithms as well as newly measured vehicle emission levels for automobiles, medium trucks, heavy trucks, buses and motorcycles.

The Volpe Center, using funds from the FHWA and 25 State departments of transportation, directed and assisted the development of the FHWA TNM to accurately analyze the extremely wide range of frequencies found in highway traffic noise. The FHWA TNM also allows noise analysts to predict noise for both constant-flow and interrupted-flow traffic and enables them to accurately predict the results of multiple noise barriers, as well as the effects of vegetation and rows of buildings along highways.

As part of the initial establishment of the FHWA technical procedures for the analysis of highway traffic noise, e.g., traffic noise measurement and prediction methodologies,the FHWA's noise regulation included references to “Sound Procedures for Measuring Highway Noise: Final Report ”[3] and to vehicle emission levels. This was done to aid in everyone's knowledge and understanding of the new technology of highway traffic noise prediction. However, since this technology has now been well established and documented for more than two decades, the FHWA noise regulation no longer needs to include any reference to a measurement report or to vehicle emission levels.

With the development of the FHWA TNM, a new state of the art highway traffic noise prediction model, the FHWA has proposed to update 23 CFR part 772 to include this new model and remove reference to vehicle emission levels. Therefore, the FHWA published a notice of proposed rulemaking (NPRM) on August 20, 2004, (69 FR 51620)proposing to require the use of the FHWA TNM or any other noise model determined by the FHWA to be consistent with the FHWA TNM methodology.

Discussion of Comments

The agency received comments from five State Departments of Transportation(Arizona, Colorado, Minnesota, New York and Pennsylvania), one State environmental agency (Minnesota Pollution Control Agency), a noise consultant from the URS Corporation, and one private citizen.

The New York and Pennsylvania State DOTs commented that they are currently using the FHWA TNM and have no objections amending the regulation to require the use of this methodology.

The Arizona State DOT commented it was in the process of implementing the use of the FHWA TNM and, thus, had no comment on the practical effects of the change in prediction models. The Arizona State DOT also offered an additional comment regarding the use of pavement types in the FHWA TNM. This comment is beyond the scope of this rule.

The Colorado State DOT commented that it generally supports the use of the FHWA TNM, and appreciated the FHWA's efforts to address the model's over predictions. This comment acknowledged the FHWA and Volpe Center's determination to correct the general over-predictions that FHWA TNM was making on vehicle emission levels. The FHWA TNM Version 2.5 is the result of these efforts, which essentially eliminates the vehicle emission level over-predictions.

The Colorado State DOT expressed its concern on using national vehicle noise emission levels (REMELs). The FHWA has determined that differences in vehicle noise emission levels are not the result of a State-specific vehicle fleet and that further studies of the effects of pavement (type, surface texture, and temperature) and atmospherics on traffic noise levels need to be completed to determine their influence on vehicle noise emission levels. Until the effects of pavement and atmospherics are researched in greater depth, the FHWA strongly recommends the use of the FHWA TNM's national vehicle noise emission levels and strongly discourages the development of State-specific vehicle noise emission levels.

The Colorado State DOT commented that it discovered several anomalies with the performance of the FHWA TNM related to pavement width, ground zones, and terrain lines. The FHWA and the Volpe Center have worked with the Colorado State DOT to resolve these issues. It was found that the anomalies stated by the Colorado State DOT were based on inappropriate comparisons. The sound level results, including trends, predicted with the FHWA TNM Version 2.5 were compared to expectations that were too generalized. The stated expectations did not always consider the specifics of each geometry and corresponding acoustical effects, and therefore were not location-dependent. A response has been sent to the Colorado State DOT on this matter offering detailed information on how to analyze highway sites to accurately identify location-dependent expectations. The FHWA and the Volpe Center will continue to offer the Colorado State DOT assistance in resolving their issues and providing guidance for those using the FHWA TNM in Colorado.Start Printed Page 16709

Lastly, the Colorado State DOT commented that it believes the FHWA TNM predicts greater noise reductions than the old prediction model, which may result in noise barrier with shorter heights. The FHWA disagrees because the validation data taken to date [see Validation of FHWAs Traffic Noise Model (TNM): Phase 1, August 2002 and Preview of Validation of FHWA's Traffic Noise Model (TNM): Phase 1 (TNM v2.5 Addendum), April 9, 2004 [4] ] indicates that the FHWA TNM performs accurately when predicting noise barrier performance, and there are no inherent biases leading to the design of shorter noise barriers.

The Minnesota State DOT and the Minnesota Pollution Control Agency provided virtually the same two comments, one related to the FHWA TNM's methodology and the uncertainty in its ability to accurately predict noise levels, and the other related to the FHWA TNM's inability to calculate L10 to L50 noise levels.

The Minnesota State DOT and the Minnesota Pollution Control Agency commented that the Stamina 2.0 based MINNOISE Version 0.2 generally proved more accurate than the FHWA TNM. This is a concern for Minnesota since Minnesota State law requiring that public health and welfare be addressed using the most accurate methods reasonable available. The Minnesota DOT is basing this comment on a report they generated entitled “Mn/DOT Noise Model Comparison Summary” which compared the FHWA TNM and the measured data at several locations. A copy of “Mn/DOT Noise Model Comparison Summary,” August 26, 2004 was provided as an attachment with Mn/DOTs comments and is available on the docket. After a thorough review and analysis of this comparison report and of additional information requested and received from the Minnesota State DOT, the FHWA and the Volpe Center found no indication that the discrepancies presented in the comparison report are due to problems associated with the FHWA TNM program. In fact, the review revealed that the discrepancies between the FHWA TNM and the measured data presented in the report are the result of an inaccurate measurement technique and three inaccurate modeling techniques.

The inaccurate measurement technique relates to the accounting for wind speeds. The wind speeds presented in the comparison report exceeded the FHWA-prescribed limit of 12 miles per hour and should have been discoounted. The wind effects on sound propagation were also not considered when comparing measured data to predicted data. When wind is accurately accounted for in the model, comparative results improve between FHWA TNM and the measured data.

The three inaccurate modeling techniques include the inaccurate use of parallel barrier configurations, ground types, and pavement types. Although the effects of parallel barrier were accounted for in the Minnesota State DOT's noise model, the effects were not accounted for in the FHWA TNM predictions. When the parallel barrier module in the FHWA TNM was used, the results again showed a more favorable comparison between FHWA TNM and the measured data. The Minnesota State DOT applied the “field grass” ground type to all FHWA TNM predicitons. This ground type is often misused, and the use of a more appropriate ground type, such as lawn, loose soil, or hard soil, again improves comparative results for FHWA TNM and measured data. Lastly, the use of “average” pavement type of roadways was applied to all FHWA TNM calculations. The use of “average” pavement type is required for federally funded projects, but can be modified if substantiated and approved by hte FHWA. Pavements that are typically considered to be “loud,” i.e., transverse-tined concrete pavements, were present for at least two of the four measurement sites. Since the comment is claiming lack of accuracy in the FHWA TNM, the actual pavement type was used despite the required use of “average” pavement type in the model. When actual pavement type is considered in the model, comparative results again improve for FHWA TNM versus the measured data.

The second comment from the Minnesota State DOT and the Minnesota Pollution Control Agency indicated that Minnesota State law requires the use of L10 and L50 descriptors, which are not provided by the FHWA TNM. The Minnesota State DOT, due to its State law, will be provided the capabilities to calculate L10 and L50 in connection with the FHWA TNM. The FHWA and the Volpe Center are currently developing these capabilities, and will provide them to the Minnesota State DOT once completed. It is estimated that the L10 and L50 capabilities will be provided to Minnesota State DOT in late Spring 2005. The Minnesota State DOT will be the only State DOT to receive this capability, and will not be required to use the FHWA TNM until this capability is provided to them.

A noise consultant of the URS Corporation indicated that he agreed with the proposal to require the use of the FHWA TNM. Additionally, the consultant recommended updating, rather than removing, the reference to the FHWA noise measurement report, indicating that local regulations using the report reference would become moot if the report reference were removed. The FHWA notes that FHWA reports may be referenced in local regulations, regardless of their inclusion in or exclusion from the FHWA noise regulations. Lastly, the consultant offered an additional comment that was beyond the scope of the NPRM.

Finally, a private citizen offered a comment stating that the regulations from 1970 are outdated and obsolete, and should be updated.

After considering all the submitted comments, the FHWA has decided to go final with the proposed rule with no changes.

Rulemaking Analyses and Notices

Executive Order 12866 (Regulatory Planning and Review) and DOT Regulatory Policies and Procedures

The FHWA has determined that this action is not a significant regulatory action within the meaning of Executive Order 12866 or significant within the meaning of Department of Transportation regulatory policies and procedures. It is anticipated that the economic impact of this rulemaking will be minimal, since the final rule simply revises requirements for traffic noise prediction on Federal-aid highway projects to be consistent with the current state of the art technology for traffic noise prediction.

This final rule will not adversely affect, in a material way, any sector of the economy. In addition, these changes will not interfere with any action taken or planned by another agency and will not materially alter the budgetary impact of any entitlements, grants, user fees, or loan programs.

Regulatory Flexibility Act

In compliance with the Regulatory Flexibility Act (RFA) (Pub. L. 96-354, 5 U.S.C. 60 1-612) the FHWA has evaluated the effects of this action on small entities and has determined that the action will not have a significant economic impact on a substantial number of small entities. This final rule addresses traffic noise prediction on certain State highway projects. As such, it affects only States, and States are not Start Printed Page 16710included in the definition of small entities.

Unfunded Mandates Reform Act of 1995

This rule does not impose unfunded mandates as defined by the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4, March 22, 1995, 109 Stat. 48). This rule will not result in the expenditure by State, local, and tribal governments, in the aggregate, or by the private sector, of $120.7 million or more in any one year (2 U.S.C. 1532). The definition of “Federal Mandate” in the Unfunded Mandates Reform Act excludes financial assistance of the type in which State, local, or tribal governments have authority to adjust their participation in the program in accordance with changes made in the program by the Federal government. the Federal-aid highway program permits this type of flexibility.

Executive Order 13132 (Federalism)

This action has been analyzed in accordance with the principles and criteria contained in Executive Order 13132, dated August 4, 1999, and the FHWA has determined that this action does not have a substantial direct effect or sufficient federalism implications on States that would limit the policymaking discretion of the States. Nothing in this final rule directly preempts any State law or regulation or affects the States' ability to discharge traditional State governmental functions.

Executive Order 12372 (Intergovernmental Review)

Catalog of Federal Domestic Assistance Program Number 20.205, Highway Planning and Construction. The regulations implementing Executive Order 12372 regarding intergovernmental consultation on Federal programs and activities apply to this program.

Paperwork Reduction Act

This final rule contains no collection of information requirements for purposes of the Paperwork Reduction Act of 1995, 44 U.S.C. 3501-3520.

National Environmental Policy Act

The FHWA has analyzed this action for the purpose of the National Environmental Policy Act (42 U.S.C. 4321 et seq.) and has determined that this action will not have any effect on the quality of the human and natural environment because it will update the specific reference to acceptable highway traffic noise prediction methodology and remove unneeded references to a specific noise measurement report and vehicle noise emission levels.

Executive Order 12630 (Taking of Private Property)

This action will not affect a taking of private property or otherwise have taking implications under Executive Order 12630, Government Actions and interface with Constitutionally Protected Property Rights.

Executive Order 12988 (Civil Justice Reform)

This final rule meets applicable standards §§ 3(a) and 3(b)(2) of Executive order 12988, Civil Justice Reform, to minimize litigation, eliminate ambiguity, and reduce burden.

Executive Order 13045 (Protection of Children)

We have analyzed this final rule under Executive Order 13045, Protection of Children from Environmental Health Risks and Safety Risks. This action does not involve an economically significant rule and does not concern an environmental risk to health or safety that may disproportionately affect children.

Executive Order 13175 (Tribal Consultation)

The FHWA has analyzed this final rule under Executive Order 13175, dated November 6, 2000, and believes that this action will not have substantial direct effects on one or more Indian tribes; will not impose substantial direct compliance costs on Indian tribal governments; and will not preempt tribal law. Therefore, a tribal summary impact statement is not required.

Executive Order 13211 (Energy Effects)

We have analyzed this final rule under Executive Order 13211, Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use. We have determined that it is not a significant energy action under that order because it is not a significant adverse effect on the supply, distribution, or use of energy. Therefore, a Statement of Energy Effects under Executive Order 13211 is not required.

Regulation Identification Number

A regulation identification number (RIN) is assigned to each regulatory action listed in the Unified Agenda of Federal Regulations. The Regulatory Information Service Center publishes the Unified Agenda in the Spring and Fall of each year. The RIN number contained in the heading of this document can be used to cross-reference this action with the Unified Agenda.

Start List of Subjects

List of Subjects in 23 CFR Part 772

  • Highways and roads
  • Incorporation by reference
  • Noise control
End List of Subjects Start Signature

Issued on: March 23, 2005.

Mary E. Peters,

Federal Highway Administrator.

End Signature Start Amendment Part

In consideration of the foregoing, the FHWA is amending part 772 of title 23, Code of Federal Regulations, as follows:

End Amendment Part Start Part


End Part Start Amendment Part

1. the authority citation for part 772 continues to read as follows:

End Amendment Part Start Authority

Authority: 23 U.S.C. 109(h) and (i); 42 U.S.C. 4331, 4332; sec. 339(b), Pub. L. 104-59, 109 Stat. 568, 605; 49 CFR 1.48(b)

End Authority Start Amendment Part

2. In § 772.13 revise paragraphs (c) introductory text, (c)(1), (c)(4), and (d) to read as follows:

End Amendment Part
Federal participation.
* * * * *

(c) The noise abatement measures listed below may be incorporated in Type I and Type II projects to reduce traffic noise impacts. The costs of such measures may be included in Federal-aid participating project costs with the Federal share being the same as that for the system on which the project is located.

(1) Traffic management measures (e.g., traffic control devices and signing for prohibition of certain vehicle types, time-use restrictions for certain vehicle types, modified speed limits, and exclusive lane designations).

* * * * *

(4) Construction of noise barriers (including landscaping for aesthetic purposes) whether within or outside the highway right-of-way.

* * * * *

(d) There may be situations where severe traffic noise impacts exist or are expected, and the abatement measures listed above are physically infeasible or economically unreasonable. In these instances, noise abatement measures other than those listed in paragraph (c) of this section may be proposed for Types I and II projects by the highway agency and approved by the FHWA on a case-by-case basis when the conditions of paragraph (a) of this section have been met.

Start Amendment Part

3. Revise § 772.17(a) to read as follows:

End Amendment Part
Traffic noise prediction.

(a) Any analysis required by this subpart must use the FHWA Traffic Noise Model (FHWA TNM), which is Start Printed Page 16711described in “FHWA Traffic Noise Model” Report No. FHWA-PD-96-010, including Revision No. 1, dated April 14, 2004, or any other model determined by the FHWA to be consistent with the methodology of the FHWA TNM. These publications are incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51 and are on file at the National Archives and Record Administration (NARA). For information on the availability of this material at NARA call (202) 741-6030, or go to​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html. These documents are available for copying and inspection at the Federal Highway Administration, 400 Seventh Street, SW., Room 3240, Washington, DC 20590, as provided in 49 CFR part 7. These documents are also available on the FHWA's Traffic Noise Model Web site at the following URL:​main.html.

* * * * *
End Supplemental Information


1.  A printed copy of “FHWA Highway Traffic Noise Prediction Model” (Report No. FHWA-RD-77-108), December 1978, is available on the docket.

Back to Citation

2.  A printed copy of “FHWA Traffic Noise Model Technical Manual” (Report No. FHWA-RD-96-010), February 1998, is available on the docket.

Back to Citation

3.  A printed copy of “Sound Procedures for Measuring Highway Noise: Final Report” (Report No. FHWA-DP-45-1R), August 1981, is available on the docket.

Back to Citation

4.  A printed copy of the “Validation of FHWA's Traffic Noise Model (TNM): Phase 1” (Report no. FHWA-EP-02-031), August 2002, and “Preview of Validation of FHWA's Traffic Noise Model (TNM): Phase 1” (TNM v2.5 Addendum), April 9, 2004 are available on the docket.

Back to Citation

[FR Doc. 05-6514 Filed 3-31-05; 8:45 am]