Noise and Vibration
The Noise and Vibration unit is responsible for developing policy and providing guidance for highway transportation related noise and vibration issues. Much of our work focuses on analyzing and mitigating noise impacts of federally funded construction projects. We also provide support for evaluating operational and construction related noise and vibration concerns. Topic areas we assist with are: noise barriers, quiet pavement, bridge noise, rumble strips, hydroacoustics, and bioacoustics.
We work with other Caltrans offices, divisions, and outside agencies to develop innovative design approaches to lower noise levels generated by transportation noise infrastructure. We can provide support in evaluating new products or processes that may lower noise impacts.
Caltrans Traffic Noise Analysis Protocol (April 2020)
The California DOT Noise Policy Protocol (PDF) presents Caltrans policies and procedures for traffic noise studies in conformance with 23 CFR 772. The Protocol is required in order to obtain FHWA approval for transportation projects authorized under title 23, United States Code. The 2011 Protocol is in effect as of July 13, 2011. It supersedes the 2006 Protocol to provide new provisions, updates, and clarifications in conformance with the revised 23 CFR 772 promulgated by the FHWA on July 13, 2010.
Caltrans Technical Noise Supplement to the Traffic Noise Analysis Protocol (September 2013)
The Caltrans Technical Noise Supplement to the Traffic Noise Analysis Protocol (TeNS) (PDF) provides additional details and expands on the concepts and procedures outlined in the Protocol. It includes technical background information relating to the analysis and reporting of traffic and construction noise and abatement strategies. The contents provided in the TeNS are for informational purposes and should not be considered as official policies, standards, or regulations unless they are referenced in the Protocol. Aside from some Caltrans-specific methods and procedures, most methods and procedures recommended in the TeNS are based on industry standards and practices. This document can be used as a guide for training purposes or as a reference to understand the technical concepts, terminologies, and methodologies of traffic and construction noise analysis.
Reasonableness Allowance - Construction Cost
Cost considerations for determining noise abatement reasonableness are based on an allowance per benefited receptor. This reasonable allowance maybe adjusted based on the most recent annual Construction Price Index. The annual price index for the fourth quarter of any year is usually posted by February of the following year. The following reasonableness allowances apply:
- The base cost allowance for any 2019 reasonable/feasible analysis should use $107,000.
- The base cost allowance for any 2018 reasonable/feasible analysis should use $95,000.
- The base cost allowance for any 2017 reasonable/feasible analysis should use $92,000.
- The base cost allowance for any 2016 reasonable/feasible analysis should use $80,000.
- The base cost allowance for any 2015 reasonable/feasible analysis should use $71,000.
- The base cost allowance for any 2014 reasonable/feasible analysis should use $64,000.
- The base cost allowance for any 2013 reasonable/feasible analysis should use $55,000.
- The base cost allowance for any 2012 reasonable/feasible analysis should use $55,000.
Noise Report Templates
The Annotated Noise Study Report (NSR) – April 2015 (DOCX) provides a template to document a project’s noise assessment findings and determine the acoustical feasibility of potential abatement strategies. The NSR template presents information in conformance with NEPA and CEQA requirements.
The Noise Abatement Decision Report (NADR) – October 2012 (DOCX) provides a template to document the reasonableness of potential abatement strategies and identify abatement strategies that meet the reasonable and feasible criteria to be incorporated into the project design. The NADR presents key information on abatement for consideration throughout the environmental review process based on the best available information at the time when the draft Environmental Document is published. The NADR is developed by a California licensed professional civil engineer using information in the NSR to establish the acoustical and nonacoustical feasibility factors, the acoustical design goal, and the relationship between noise abatement allowances and the engineer's cost estimate.