Tire Pavement Noise

FHWA Expert Task Group

The FHWA Expert Task Group (ETG) was a recommendation that came out of the 2004 FHWA Tire-Pavement Noise Strategic Planning Workshop. The purpose of the ETG is to establish and help guide tire/pavement noise measurements in the U.S. The primary purpose of the measurement guidance is to identify goal-based measurement methodologies and encourage consistency of the application of each type of methodology throughout the U.S.

The ETG has been charged with the following tasks:

• Develop provisional standards for consideration by AASHTO for measurement of tire/pavement noise. This may include the possible writing of a provisional standard, adapting an existing standard, or the adoption of an existing standard for tire/pavement noise for:
  • Source Measurement Methodologies: On-board Sound Intensity (OBSI) and/or Close Proximity (CPX) methodologies
  • Wayside Measurement Methodologies: time-averaged and/or statistical pass-by methodologies
  • Pavement Noise Absorption Measurement Methodologies: impedance tube testing, impulse response measurement - extended surface and /or ground impedance using effective flow resistivity methodologies

    Although provisional standards are being developed, at this time FHWA is not endorsing any particular methodology for measuring tire/pavement noise.

• Coordinate with international groups and various practitioners in the U.S. to advance measurement methods and establish the correlation between various types of measurements.
• Promote implementation of provisional standards by practitioners.
• Evaluate and refine the provisional standards to facilitate adoption as full standards

  Although AASHTO provisional standards will be developed for several measurement methodologies, the ETG decided to look at the OBSI methodology first. As of June 2006, the first version of a draft AASHTO provisional standard for the OBSI methodology has since gone through several revisions based on input from ETG members, TRB ADC40 members, and others. The standard is currently divided into two parts: equipment specification and standard practice. The ETG will review the latest drafts once they are distributed.