The Volpe Center Acoustics Facility, in support of the Federal HighwayAdministration (FHWA) and the California Department of Transportation(Caltrans), has been conducting a study to quantify and assess the accuracyof FHWA's Traffic Noise Model (TNM) and make recommendations on its use. The TNM Validation Study involves highway noise data collection and TNMmodeling for the purpose of data comparison. Phase 1 of the study has beencompleted. For this phase, over 100 hours of traffic noise data werecollected at 17 highway sites around the country.