PT-5: Quiet Pavement

Post by JanB Aug 11th, 2010
at 3:29 pm

PT-5
General Comment:
Many Park roads – Auto Tour Routes in battlefields, Generals Highway in Sequoia NP, South Rim Village in the Grand Canyon, are low speed roads that don’t qualify for the credit.
NPS-BG

Post by JanB Aug 11th, 2010
at 3:29 pm

PT-5
General Comment:
It seems as though some amount of quietness is achieved with open-graded asphalt mixes, which have shorter performance lives than what is normally used. On page 2, the statement is made that “open-graded asphalts have shown noise reductions from 3-8 dBA…” This seems a very minor benefit for using a material with a shorter lifespan.
NPS-BG

Post by Gary A Jun 27th, 2010
at 12:18 pm

Table TP-5.1 needs to be modified to more accurately reflect the proper procedures to be used for the OBSI testing. Testing should be done at the actual speed limit to reflect the conditions that will exist as actual traffic travels the roadway.

Suggested Revised Table PT-5.1

Maximum Average Noise
Facility Post Speed Test Speed 2 Points 3 Points
35 mph 35 93 90
45 mph 45 96 93
55 mph 55 99 96
65 mph 65 102 99

Details – The entire length of each lane being considered for credit should be tested.

Approach & Strategies – Next generation concrete surface, NGCS, should be included in the pavement design guidelines.

A large amount of research has been completed in the past few years regarding pavement noise. The 2002 reports referenced may not contain the most current results.

States with Quiet Pavements
1. There is more current data available on the Arizona work.
2. Minnesota and Kansas also have quiet pavement research.

Traffic Noise
1. Table PT-5.2 should be changed to include NGCS.
2. Pavements are not normally designed thicker to accommodate grinding.
3. Cost per lane mile of grinding is wrong. Various examples would be 5year average costs for:
a. Washington - $9.45/SY or $67,372.80/lane mile
b. Kentucky - $2.67/SY or $18,796.80/lane mile
c. North Dakota - $2.27/SY or $15,980.80/lane mile

Need to define testing procedure!

The points are awarded for initial construction with no acknowledgement regarding acoustic longevity. A meaningful rating system would define a value that is either maintained or achieved over a reasonable portion of the expected pavement life.

The rating system focused exclusively on the tire-pavement noise interaction, which may or may not be the significant noise generation mechanism. A better approach would be to establish the rating system by the “designed: noise levels at the receivers as this reflects the actual quality of the life in the communities. By establishing the rating system based on receptor or community levels, the total noise impact is evaluated and considers all the noise mitigation options as a systems approach. This provides credit for real impacts, allows designers more innovation and considers actual traffic fleet composition in the noise generation process. Quiet pavements do little in regards to reducing truck-generated noise and trucks add additional design challenges to address the elevated stack noise sources. By developing a point system based on wayside noise levels (instead of tire-pavement), you motivate the designers to improve the quality of life of the communities.

Post by JudithR Jun 25th, 2010
at 1:23 pm

There need to be more details about the OBSI testing. How long after construction should the OBSI data be collected? What should be done to determine that the area of a highway section that was tested is representative (in terms of sound level) of the rest of the section? Research has shown that OBSI levels can vary by a couple decibels along one section of a highway.

Post by JudithR Jun 25th, 2010
at 1:23 pm

Research
Traffic Noise, 1st sentence: This is a run-on sentence and needs to be fixed.

Paragraph just below Figure PT-5.4: Either “a” needs to be removed or “s” on “surfaces” needs to be removed from, “… than a standard pavement surfaces.” Also there is a plural issue in the second to last sentence.