Welcome to the 25th Anniversary celebration page for FHWAs Traffic Noise Model. The first version of TNM was released in 1998 and we've come a long way since. Please join us in commemorating 25 years of collaboration, feedback, updates, improvements, and overall development! This work would not have been possible without the State Department's of Transportation, expert private consultant teams, the US Department of Transportation's Volpe Center, and past and present Federal Highway staff. We sincerely appreciate all of your work, insight, and ideas. We look forward to continuing to analyze noise with the best-available technology to generate the greatest public good from our highway projects.
Anniversary Brochure
We have developed a printable brochure for use in public involvement, training, or as a meeting material. The brochure is viewable online by clicking the image below or as a printable PDF. It is best printed in Landscape mode on an 8.5 x 11 inch sheet.
History
Need for Noise Analysis and Regulatory Context
The Federal Aid Highway Act of 1956 led to a roadway construction boom in the United States. While the roadways connected goods and people and made long distance travel faster and safer, there were some negative effects from the rapid expansion of the highway system. By the 1960s the public was expressing increasing concern over the negative externalities of highway planning and construction; including air quality and noise impacts. This resulted in several environmental and public health protection laws, regulations, and policies being passed in the late 1960s and early 1970s.
Although Title 23 of the United States Code (Highways) was enacted in 1958, Section 109 subsections (h) to (j) were not added until the 1970 amendments; and subsection (i) did not include Highway Noise until the 1973 amendments. This new text in 23 USC 109(i) directed the Secretary of Transportation to consult various parties and implement noise level standards on Federal-aid Highways. In response to this mandate, in June 1972, the FHWA published 'Noise Standards – Proposed Policy and Procedure Memorandum' in the Federal Register (Vol. 37, No. 114, Page 11730). This became known as PPM 90-2 and it directed States to 'compute' anticipated noise levels.
Calculation, Computation, and Modeling before TNM
PPM 90-2 was the first FHWA rule that specified a prediction method for highway noise analyses. It allowed the use of the NCHRP 117 Report's method and/or the DOT Transportation Systems Center (TSC) method outlined in DOT-TSC-FHWA-72-1 - the Manual for Highway Noise Prediction (Appendix B). The Appendix B method included the use of a basic computer program (Traffic Noise Prediction Model MOD 2). This early program was made to run an on IBM 7094 computer and was coded in FORTRAN IV. A 1974 update to 23 CFR 772 reiterated the use of NCHRP 117 (as modified by this time by Report 144), of the FHWA Form 1443 – Barrier Nomograph, and of the Transportation Systems Center method. In addition to these methods, several states developed their own computer programs.
Later still, in the late 1970s, FHWA developed and released SNAP (Simplified Noise Analysis Program); and STAMINA (Standard Method In Noise Analysis) with the associated OPTIMA, which helped optimize noise mitigation based on the results from STAMINA. STAMINA was a major update to the practice of noise prediction because it made use of extensive field measurements and research in its acoustic database. By 1978, FHWA released an update to 23 CFR 772 requiring the use of STAMINA as the only prediction method for Federal aid highways projects. STAMINA/OPTIMA were in use for decades, however by the early 1990s, a major update was proposed for release as STAMINA 3.0. Due to the extensive updates, new acoustic research, and improved computing power it was instead released as an entirely new model: the first Traffic Noise Model (TNM) 1.0.
Future plans for the TNM 3 series include reducing memory usage, improving contours and import/export options, and enhancing diagnostics and documentation. Acoustic research by the National Cooperative Highway Research Program (NCHRP) with support and participation from FHWA and the Volpe Center is underway. We expect this research to produce enough acoustic information to update the underlying assumptions in TNM. Plans for TNM 4.0, include the possibility for new vehicle types and sub-source heights pending the results of the research. FHWA is also considering adding new mitigation capabilities, such as new pavements and barrier design options; improving or automating some data importation; and integrating some existing standalone tools.
TNM Anniversary Video
Please visit again to view the Anniversary video! Our team interviewed multiple people from the private sector, academia, and government about their recollections of noise modeling history and the development of TNM.
Public Roads
The FHWA authored a brief Public Roads article on the occasion of TNM's 25th Anniversary. It includes a history of TNM as well as a look toward the future.
