Office of Environmental Management

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NOISE ABATEMENT MEASURES

Noise abatement is considered at all impacted noise sensitive land uses for which there is a NAC.  Abatement measures considered include traffic management, alignment modifications, noise buffer zones through application of land use controls and noise barriers.

Noise barriers reduce noise levels by blocking the sound path between a highway and noise sensitive site. To effectively reduce traffic noise, a barrier must be relatively long, continuous (with no openings), and of sufficient height. For a noise barrier to be considered feasible and cost reasonable, the following conditions must be met:

• At least two impacted receptors must be provided a noise reduction of 5 dB(A) or more to be considered feasible.
• A noise barrier must also attain the Noise Reduction Design Goal (NRDG) of 7 dB(A) for at least one benefited receptor.
  • Of importance, this receptor may also have been previously identified as meeting the feasibility requirement of receiving a 5 dB(A) reduction (first bullet).
• The cost of the noise barriers should not exceed $64,000 per benefited receptor.
  • This is the upper cost limit established by FDOT (2024).
  • A benefited receptor is defined as a recipient of an abatement measure that experiences at least a 5 dB(A) reduction as a result of providing a noise barrier.
  • The current unit cost used to evaluate cost reasonableness is $40 per square foot (sq. ft.).
• The noise barrier must meet design/construction, safety, access, right-of-way, maintenance, drainage and utility criteria to be considered feasible.
• The viewpoint of the property owner of the benefited noise sensitive land uses is considered.

NOISE METRICS

Noise levels developed for FDOT highway traffic noise analyses are expressed in decibels (dB) using an “A”-scale [dB(A)] weighting. This scale most closely approximates the response characteristics of the human ear to typical traffic noise levels.  Reported noise levels are reported as hourly equivalent noise levels [Leq(h)]. The Leq(h) is defined as the equivalent steady-state sound level that, in an hourly period, contains the same acoustic energy as the time-varying sound level for the same hourly period. Use of these metrics is consistent with the 23 CFR 772 requirements.

Sources: 23 Code of Federal Regulations Part 772 (23 CFR 772), "Procedures for Abatement of Highway Traffic Noise and Construction Noise", Federal Register, Vol. 75, No. 133, Tuesday, July 13, 2010; pages 39834‐39839. FDOT, "Highway Traffic Noise", Part 2, Chapter 18. Project Development and Environment Manual, FDOT, Tallahassee, July 1, 2023.

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Noise Tools & Resources

NOISE BARRIER INVENTORY

The Federal Highway Administration's (FHWA) highway noise regulation (23 CFR 772.13(f)) requires each state’s Department of Transportation (DOT) to maintain a Noise Barrier Inventory of all constructed noise abatement measures. FDOT Noise Barrier Methodology Flowchart. The inventory must include the following:

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FHWA'S TRAFFIC NOISE MODEL (TNM)

FHWA’s Traffic Noise Model (TNM) Version 2.5 (2004) is required for use on all Federally funded highway projects, per 23 CFR part 772. Training on this model is available here: TNM Training (FHWA December 2022).

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TEMPLATES & SPREADSHEETS

FDOT SLU Worksheet (December 2023): This worksheet aids the Noise analyst in evaluating if a noise barrier is a reasonable and feasible form of abatement for non-residential land uses.  Guidance for SLU Worksheet

FDOT Traffic Data for Traffic Noise Spreadsheet (February 2022): This worksheet is required for use by the Noise Analyst to post-process traffic data to be entered into the Traffic Noise Model. It is required to be submitted alongside TNM files.

PD&E Noise Study Report Template (February 2025): This template may be used to compile Noise Study Reports for PD&E projects.

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NOISE POLICY, RESOURCES & GUIDES TABLE (PDF)