by Doug Barrett
The Transportation Research Board (TRB) held its 90th Annual Meeting in Washington DC from January 23-37. Although I’ve attended many of these meetings, the size and breadth of the annual meeting always astonish me. This year’s meeting set a new record (over 10,900) and, as usual, there were workshops and sessions covering everything under the sun related to transportation.
As the primary source of traffic noise, tire-pavement noise continues to be a hot topic in the highway noise world. Although the ADC40 Committee on Transportation-Related Noise and Vibration is just one small part of the annual meeting, in recent years the Committee has broadened its scope by co-sponsoring sessions with other committees. This year, ADC40 co-sponsored three workshops or sessions on tire-pavement topics. Sunday morning’s workshop titled “Implementing Noise-Reducing Pavement Research, an International Perspective: Making Pavement Research Results Work in Practice” was followed by Monday’s session on the “Effect of Asphalt Mixture Composition on Friction and Noise,” and Wednesday’s “Tire-Pavement Noise” session. Co-sponsors of these workshops/sessions included the Committees on Surface Properties-Vehicle Interaction (AFD90), Characteristics of Asphalt-Aggregate Combinations to Meet Surface Requirements (AFK40), and Pavement Maintenance (AHD20).
One topic covered during these sessions was the use of On-Board Sound Intensity (OBSI) measurements. OBSI has gained widespread acceptance throughout the U.S. as a standardized approach for quantifying tire-pavement noise. Recently, HMMH conducted OBSI measurements at locations throughout Virginia, on behalf of the Virginia Department of Transportation (VDOT). The VDOT measurements are part of an ongoing program to document the long-term benefits of pavement overlays. OBSI measurements, however, not only can document the noise reduction benefits of quieter pavements, but also can help to identify louder pavements. As the noise program manager for another DOT said, his state’s ongoing OBSI test program is not about finding the quietest pavements – it’s about identifying the loudest ones!