Re ECF Project: 2004-23

Project Title: Towards developing an engineering strategy to reduce tire-pavement noise

Applicant: Hong Kong Polytechnic University (Dr. HUNG Wing-tat)

Total Approved Grant: $309,176.28 (ECF&WWGF: 50/50)

Duration: 15/11/2005 to 14/5/2007

Project Status/Remarks: Completed

Scope:
The objectives of this proposed research are as follows:

  1. to design and fabricate a trailer-based device employing the Close Proximity Method to measure the tire-pavement noise;
  2. to conduct on-road tire-pavement noise surveys employing the trailer over selected low-noise pavement segments;
  3. to conduct roadside traffic noise measurements over selected points along the road segments surveyed in b) above;
  4. to assess noise-reduction performance of various types of road pavements;
  5. to evaluate the effects of different tire constructions and conditions on tire-pavement noise; and
  6. to provide recommendations that facilitate the development of an engineering strategy to reduce tire-pavement noise.

Summary of Findings/Outcomes :
A CPX trailer with an enclosure for measuring tire-pavement noise was designed and fabricated based on the draft ISO specification, i.e., ISO/CD 11819-2 Acoustics - Measurement of the influence of road surfaces on traffic noise - Part 2: The close-proximity method. A single test tyre with two mandatory microphones is placed inside the enclosure. The trailer has many special features including a mechanical lifting device and removed tyre notches to allow measure the background noise using the "lifted / removed tyre" method and a digital camera to record the tyre road surface. The trailer is specially designed to be towed by a four-wheel drive vehicle which has quiet tyres and produces minimal vibration noise. The trailer has been certified according to all the requirements stipulated in the ISO Standard 11819-2. Road tyre noise measurements on many road sections with various road surfacing materials were conducted. Conventional roadside traffic noise measurements were conducted in selected road sections to compare the CPX results. The two sets of measurements produced consistent results. With the CPX assembly, it is possible to assess the road noise reduction performances of various road surfacing materials and the tyre properties. An engineering solution to reduce road tyre noise can then be formulated.