HMMH developed Version 1.0 of the Federal Highway Administration’s Traffic Noise Model (FHWA-TNM), in the mid 1990’s. As part of the development, HMMH designed TNM’s:
- User interaction
- Detailed functions
- Input methods
- Emission-level analysis
In addition, HMMH designed, wrote, and tested all acoustical algorithms and code. HMMH also wrote TNM's Technical Manual and drafted its User's Guide.
HMMH is currently leading the research team conducting National Cooperative Highway Research Program (NCHRP) 25-34: Supplemental Guidance on the Application of FHWA’s Traffic Noise Model (TNM). The goal of the 30-month research effort is to provide guidance on best modeling practices for scenarios for which there is currently limited or no technical guidance. In addition to recommending best practices, the research team will assess both the sensitivity of the model to the proposed methodologies and the accuracy of the results obtained using the practices.