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Standard methodology for analyzing noise and vibration impacts on terrestrial wildlife


The objective of this project is to develop a consistent methodology for analyzing noise and vibration impacts on terrestrial wildlife species, mainly mammals and birds. Analyzing the effects of noise and vibration on wildlife requires expertise in two different technical fields to understand the level of noise and vibration affecting habitat or animals at different distances from where it is generated and to understand how that noise and vibration might affect different species. The goal of this project is to develop a framework for standard metrics and procedures for the state Department of Transportations (DOTs) to conduct noise analyses of highway projects on those species based on science and good practice.

State and federal wildlife regulatory agencies are implementing requirements to meet certain noise thresholds for highway transportation projects to minimize noise and vibration impacts on wildlife. These impact analyses may be required during the Section 7 consultation process or for other wildlife impact analysis under NEPA and under state laws such as CEQA in California or SEPA in Washington State. Currently, there is little-to-no guidance from federal agencies on how to conduct the noise and vibration analyses specific to wildlife. This lack of guidance results in a wide array of different approaches to noise studies/analyses that may be inaccurate, non-comparative from state to state (or study to study), or completely unnecessary. In addition, rework of efforts to address these impacts in a manner acceptable to state and federal wildlife regulatory agencies, often results in project delivery delay.

Refining previous methodologies and collecting information on past acceptable noise impact assessment practices may help direct future work to make noise impact assessment methodologies more standardized. Development of noise and vibration assessment guidance could be a precursor to the Federal Highway Administration (FHWA) and U.S. Fish and Wildlife Service (FWS) creating an agreement on approaches to noise and vibration analysis methodologies.

Noise impacts to wildlife vary by species as different animals and populations react in disparate ways. Noise impacts to species are also time-dependent, based on breeding season, rearing, fledging, or migration. All of these factors must be considered in determining whether a noise impact may rise to the level of ‘take’ under the Endangered Species Act. The following are examples of noise disturbance to various animals:

  1. Some nesting bird species may be more disturbed by a nearby researcher than construction occurring 100 yards away.

  2. If it is a sensitive birthing period, a species may go to great lengths to avoid an impact their offspring and possibly leave favored habitat to do so.

  3. A raptor might be tolerant to a disturbance when the young are very small, but when they get close to fledging, disturbance could make the young leave the nest too soon and lower their chance of survival.

  4. Noise can interfere when a species relies on their hearing to find mates or food, or for echolocation, or to avoid predators.

  5. Sound vibrations, or percussive sounds, may cause a species to abandon an area.

Individuals of certain animal species may become habituated to anthropogenic sound, so examining increases in noise levels over ambient levels may be a better measure of an impact than overall noise levels. Taking noise habituation into consideration when evaluating noise effects on wildlife may reduce the need for unnecessary mitigation on highway projects.

This research will help define the procedures and metrics for conducting analyses to assess noise and vibration impacts on subject species.

This research task supports the Committee on Environment and Sustainability’s (CES) initiative to streamline the environmental review process and their promotion of practices that encourage interagency cooperation and coordination in the resolution of environmental issues.


The objective is to develop a consistent methodology for analyzing noise and vibration impacts on different subject species. The desired final outcome would be standard metrics and procedures for the DOTs to conduct analyses of the potential effects of noise and vibration from highway projects on land-based wildlife based on science and good practice.


A summary of this existing information and framework or methodology for conducting noise and vibration analyses for different terrestrial species would assist DOTs to expedite noise and vibration impact analyses thereby saving substantial time and money by addressing this issue in the impact assessment phase. Consistency in the methodologies used by DOTs will result in studies that are comparable and improve the predictability of the level of effort needed for these analyses.

Related Research:

A cursory search of TRID () and Research in Progress database () under key words “terrestrial noise” did not provide any previous work specific to methodologies for analyzing noise and vibration impacts on different terrestrial species. Currently, Caltrans is the only state that has available protocol for addressing noise impacts to birds and bats.


Task 1: Conduct Interviews of DOTs and of Oil and Gas Companies

Conduct interviews of DOTs in representative ecoregions for information on species consultations or for existing guidance. This will help narrow the species list and identify what species are of most concern to DOTs as well as identify which species or groups of species would benefit from developed noise and vibration assessment guidance. Staff from California DOT should be included to learn about their existing protocol for addressing noise impacts to birds and bats. Altogether, 19 states have expressed an interest in this type of methodology, including AL, AZ, CO, ID, IL, KY, ME, MT, ND, NH, NV, OH, OK, UT, VA, VT, WV and WY.

Task 2: Literature Review

Conduct a literature review focusing on those species of concern and ecoregions as identified in Task 1. The proposed research will include a more detailed search of TRB’s TRID () and Research in Progress () databases and a detailed literature review and survey of highway agencies and other industries with a focus on noise and vibration assessments of differing environments and species. Identify data gaps in existing literature and practice. Survey staff at USFWS and state Fish and Game agencies to gather input, direction, or requirements they have included during their consultations with stakeholders and evaluate consistency across the country. Compile findings from the interviews and literature review regarding methodologies used for noise and vibration analysis generally and by species group and identify the best available science used by the regulatory agencies. Develop a draft report, disseminate draft for review, incorporate comments, and prepare a final literature review report.

Task 3: Develop Guidance Strategies for Methodologies Used for Analyzing Noise and Vibration Impacts on Various Wildlife Species

Develop template protocols to analyze noise and vibration impacts for priority species groups/situations that reflect the regulatory needs of the DOTs and will yield robust results under feasible budgets as well as an overall summary of current practices to assist in developing protocols for other species.

Task 4: Summary of Results/Final Report

Combine the highlights of the results of Tasks 2 and 3 into a concise summary document targeted at DOT biologists and project managers. Make recommendations on where further research is needed.


The results of this research would be used in project planning to estimate the level of effort needed to analyze and mitigate noise and vibration impacts from a project and by DOT biologists and noise specialists to conduct the analyses. It could also be used as the basis for discussions between FHWA and USFWS for a more formal agreement on standard methods. The summary document will be disseminated to all state DOTs and it is anticipated that webinars and/or trainings will be offered to state DOT noise and wildlife specialists on how to implement the guidance.

Sponsoring Committee:ADC40, Transportation-Related Noise and Vibration
Research Period:24 - 36 months
Research Priority:Medium
RNS Developer:Noel Alcala, Ohio DOT, Kris Gade, Arizona DOT
Date Posted:12/06/2019
Date Modified:12/10/2019
Index Terms:Sound level, Noise, Traffic noise, Vibration, Wildlife,
Cosponsoring Committees: 

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