PT-5: Quiet Pavement - 2-3 points

Goal

Improve human health by reducing tire-pavement noise.

Requirements

At least 75% of the traveled lane area where the speed limit is greater than 30 mph use a pavement surface course that produces tire-pavement noise levels at or below those listed in Table PT-6.1. Testing shall be done using the On-Board Sound Intensity (OBSI) method with the ASTM Standard Reference Test Tire (SRTT). Table PT-6.1 describes test vehicle speed parameters. This credit can earn 2 or 3 points depending upon the level of noise reduction achieved.

If the project has multiple speed limits, each section that applies to this credit shall be tested according to its posted speed limit as shown in Table PT-6.1.

Required Documentation

This credit is satisfied after the construction process. Submit the following two items:

•  A calculation to indicate the percentage of pavement surface area that is surfaced with quiet pavement. This calculation may be built into the submitted project documents.
• OBSI test results. As a minimum they should include the procedure followed, testing vehicle speed, average OBSI reading in dBA and a general description of the pavement type tested. during the design process. Standard project documentation should indicate pavement sections to be built or reused, highlighting the sections designed to be long-life pavements, and clearly labeling the associated surface area for that section.

Example Calculation

An existing four-lane divided freeway is to be resurfaced with asphalt rubber open graded friction course (ARFC). Ten lane-miles of freeway (5 in each direction) with 12-ft wide lanes are to be resurfaced. Also, two 14-ft wide off-ramps, each 2,000 ft long, and the existing 10-ft wide shoulders are to be resurfaced with dense-graded HMA (not a quiet pavement). The posted speed limit for the freeway is 65 mph while the posted speed limit for the off-ramps is 40 mph.

The area of the shoulders is excluded because it is not in the travelled lanes. OBSI tests after construction were done at 60 mph with the ASTM SRTT on the inside northbound lane. Results showed that the average OBSI level on the ARFC was 96.5 dBA. No tests were run on the ramps because they were not surfaced with quiet pavement and were excluded from the quiet pavement surface area calculation.

This project would earn 2 points because the minimum area requirement of 75% was met (91.2% was achieved) and the maximum noise level as measured by OBSI of 99 dBA was not exceeded.

Comments

Documentation

Tasks: