Residents torn over new sound walls along freeway in West Covina

Started by bing101, August 21, 2016, 11:23:52 AM

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bing101

http://abc7.com/society/residents-torn-over-new-sound-walls-along-freeway-in-west-covina/1477746/


Well as usual a sound wall causes NIMBY issues in the West Covina section of the 10 freeway.


Converted thread title to sentence case. –Roadfro


hotdogPi

threadTitle = threadTitle.lower()

But seriously, you don't need to put the thread title in all caps.
Clinched, minus I-93 (I'm missing a few miles and my file is incorrect)

Traveled, plus US 13, 44, and 50, and several state routes

I will be in Burlington VT for the eclipse.

roadfro

^ I'm guessing he copy-pasted from the headline in the linked article, which is also in all-caps. I changed it.
Roadfro - AARoads Pacific Southwest moderator since 2010, Nevada roadgeek since 1983.

jakeroot

According to WSDOT, the U.S. Congress passed legislation in 1976 which requires states to provide abatement for highway noise (considered an environmental impact) as a part of all Type I Federal Aid projects at impacted locations where it is reasonable and feasible.

I'm not sure what qualifies as "Type I", but I'd reckon that the sound walls may have been required in this case.

SeriesE


compdude787

Is it just me, or do those sound walls just seem quite a bit taller than most?

hotdogPi

Clinched, minus I-93 (I'm missing a few miles and my file is incorrect)

Traveled, plus US 13, 44, and 50, and several state routes

I will be in Burlington VT for the eclipse.

jeffandnicole

QuoteWest Covina resident Lisa Gable said she was frustrated by the 160-foot tall brownish-orange sound wall on I-10, right next to her house.

If it was 160 feet tall, that would be about 120 feet taller than needed.  I think someone exaggerated or the paper didn't quote the correct figure.  A 5-stack is only about 100 feet tall, for comparison.

QuoteNot everyone cares about the look or the noise as much as they care about the size. One restaurant manager said he lost a significant amount of clients because the wall covers the view of the restaurant from the highway.

If they were good clients, they would be destined to his restaurant, rather than driving along a highway and just happened to see it.

hotdogPi

Quote from: jeffandnicole on August 22, 2016, 09:19:41 AM
QuoteWest Covina resident Lisa Gable said she was frustrated by the 160-foot tall brownish-orange sound wall on I-10, right next to her house.

If it was 160 feet tall, that would be about 120 feet taller than needed.  I think someone exaggerated or the paper didn't quote the correct figure.  A 5-stack is only about 100 feet tall, for comparison.

Most likely: It was 50 feet. Someone misinterpreted it as 50 meters and converted it to 160 feet.

Second most likely: Someone is trying to set a world record for highest wall.

Third most likely: Someone's trying to compete with Donald Trump.

Fourth most likely: "One sixty-foot wall" became "160-foot wall".

There are other possibilities.
Clinched, minus I-93 (I'm missing a few miles and my file is incorrect)

Traveled, plus US 13, 44, and 50, and several state routes

I will be in Burlington VT for the eclipse.

kkt


andy3175

Drove past the construction for this soundwall yesterday, and work appeared to be continuing apace. I am not sure if there is planned expansion also underway to incorporate a carpool HOV lane for this segment or not.
Regards,
Andy

www.aaroads.com

The Ghostbuster

I just read the article. Those sound walls don't look that bad to me.

djsekani

Quote from: andy3175 on August 22, 2016, 12:46:30 PM
Drove past the construction for this soundwall yesterday, and work appeared to be continuing apace. I am not sure if there is planned expansion also underway to incorporate a carpool HOV lane for this segment or not.

The HOV lanes are the main reason for the construction. They're closing the gap between the 605 and the 57. I've read that they may eventually be tolled, but that's another project anyway.

sparker

One of the interesting (and not talked about) side-effects of sound walls is an artifact of the fact that sound waves are affected by gravity.  Most sound walls are intended to stave off complaints from the neighborhoods immediately adjacent to the freeways.  Engineers will take SPL (sound pressure level) meters out to the areas and cobble up some height measurements for the walls based upon the readings.  The wall gets built, and they go out there again and determine the difference in dB (decibels) between "before" and "after" for a given location, normally along the nearest adjacent street paralleling the freeway.  If it's down a certain level (likely 18-24dB or more), they call it a day; if under that figure, they add some height to the wall. 

What walls do to the noise generated by the traffic on the freeway is to amplify that noise directly above the freeway; it's a phenomenon known in the audio industry as "horn-loading"; with only one direction (besides laterally along the freeway itself, which makes little or no difference since the facility itself IS the noise generator) to exhaust itself the sound waves self-amplify vertically.  Eventually those waves are dissipated by gravity and arc outwards from the vertical trajectory -- and eventually return to ground level a certain distance from the freeway/noise generator.  That distance is dependent upon a lot of variable factors: the distance between the sound walls on either side of the freeway, the height of the wall, and even the mean frequency generated by the traffic (diesel engines tend to produce a lower frequency noise spectrum than do gasoline engines). 

Back in the early 90's sound walls were constructed along the CA 85 freeway between I-280 and CA 237; the wall height was about the same as the clearance height of the bridges over the freeway (15-16 feet).  A close friend owned and rented out a house on Wright Street in Sunnyvale, about 6 blocks east of the freeway.  Immediately after the walls were installed, he received complaints from his tenant about increased noise levels -- that sounded suspiciously like freeway noise.  I'm in the speaker design and development business, so he called me for advice; I went over to the rental property and measured the SPL there (you gotta have a portable SPL meter in the speaker business!) as well as on all the parallel streets between Wright and the freeway, as well as 3-4 streets east of there.  While the noise level was relatively low on the street immediately adjacent to the freeway, it increased slightly on the next street over, slightly more on the next street, and ramped up until halfway between the street just west of Wright and Wright Street itself -- right smack on the back patio of my friend's rental house! -- it was about 12-15dB higher than immediately adjacent to the freeway.  East of there the process reversed, each street had slightly lower levels than the next until no significant sound level was detected.  Just my buddy's luck -- his property was the location where the freeway sound waves touched down, diminished by about 10-15dB from the source (we measured that on an overpass) but higher (again about 10-15dB) than the rest of the immediate area.  The noise was centered at about 250 Hz (for you musicians out there, just under middle "C" on a piano, which is 261.6 Hz).

My friend has never been the type to take things lying down, so he complained to Caltrans District 4 about the problem -- but they dismissed it with a "not too bad considering" response, saying there was nothing they could do about it short of capping the freeway, which they were (obviously) not about to consider.  I even wrote a supporting letter suggesting that they place lateral "shelves" along the sound wall to break up the upwards standing waves; there response was that they would take that concept into consideration in future placements, but were not about to retrofit the CA 85 walls in any case. 

He has a new tenant (a divorced college buddy) who tends to play his TV and audio systems louder than normal, so the noise is less of an issue than previously -- but the last time I was on the property, I could still hear the freeway noise distinctly in the back yard.  You can only dissipate sound waves with distance; at close range, you can merely relocate them!

skluth

^^^^^^^^^^^^^

Bumping this topic because a) I think it's interesting and b) it was referenced recently in another thread.

I worked as an AG in the Navy in the first half of the 1980's, which is weather and oceanography. We learned how the speed of sound is affected underwater mostly by temperature and pressure variations, and less by salinity variations. The computers in Monterey worked out sound profiles that we would send to the OS's who listened for subs underwater (like Jonesy in Hunt for Red October). Depending on the conditions, it could travel downward or upward - and in the right conditions sound will propagate for hundreds of miles. We never considered gravity, but the ocean is a lot more dense a medium than air.

I thought your approach for a solution to the noise was interesting. Have you seen where 'lateral "shelves" along the sound wall' were able to improve the wall's effectiveness? Any other ideas on how to improve sound wall efficacy?

sparker

^^^^^^^^^^
On my last trip to SoCal over New Years' I noticed that some newer soundwall installations employed very irregular "rocky" surfaces, likely intended to break up standing waves that would propagate along the wall's surface -- similar to my suggestion of lateral "shelves" but undoubtedly simpler to cast into the wall surface.  I'm in the audio business (specialty "high-end" speakers and components), and wall treatment -- often with irregular foam surfaces (obviously not practical for a freeway sound wall!) has proven to be quite effective to reduce standing wave issues.   Within a nominal room listening situation, breaking up a room wall with bookshelves or even shelving with decorative items on them accomplishes much of that task, although that wouldn't be useful in a controlled test environment.  But have yet to see any horizontal shelves as such deployed along freeways; up here in the Bay Area, most soundwall installations tend toward the traditional walls with sporadic decoration.  However, stay tuned -- the project involving widening I-880 in the Hayward/San Leandro area is just winding down; the walls will be the last thing to go up -- and I'm on that freeway at least once per month, so I'll make it a point to check to see what sort of treatment they're applying to the walls and post accordingly. 

ErmineNotyours

A few years ago I noticed this installed above the reversible Express Lanes on the I-5 Ship Canal Bridge, to stop the reflection of sound off the upper deck.  Something similar was planned for the Alaskan Way Viaduct, but they decided to tear it down instead.

sparker

Quote from: ErmineNotyours on April 05, 2019, 11:14:16 PM
A few years ago I noticed this installed above the reversible Express Lanes on the I-5 Ship Canal Bridge, to stop the reflection of sound off the upper deck.  Something similar was planned for the Alaskan Way Viaduct, but they decided to tear it down instead.

Those are a version of "box traps"; smaller versions are often used in recording studios to lessen standing waves, particularly at or near room corners.   If implemented correctly -- with textured inner sides to further break up air movement -- they're pretty damn effective at absorbing audible frequencies. 

SoCal Kid

Are spurs of spurs of spurs of loops of spurs of loops a thing? ;)

compdude787


sparker

Quote from: compdude787 on April 19, 2019, 03:33:03 PM
Quote from: SoCal Kid on April 07, 2019, 09:19:05 PM
Quote from: SeriesE on August 22, 2016, 01:18:33 AM
Should've put up a clear sound wall, I guess.
Hmm, never heard of that :Hmm:

It's quote common in Europe.

Unless the "clear" sound wall has some sort of baffles built (or cast) in to break up the sound waves that would otherwise project vertically from its top edge (and, as previously stated, return to ground some distance away), it would display the same issues as any other roadside wall.  Not all that hard to do -- but would likely add some nominal cost to any wall project for parts and/or labor.

skluth

Quote from: sparker on April 05, 2019, 04:15:23 PM
^^^^^^^^^^
On my last trip to SoCal over New Years' I noticed that some newer soundwall installations employed very irregular "rocky" surfaces, likely intended to break up standing waves that would propagate along the wall's surface -- similar to my suggestion of lateral "shelves" but undoubtedly simpler to cast into the wall surface.  I'm in the audio business (specialty "high-end" speakers and components), and wall treatment -- often with irregular foam surfaces (obviously not practical for a freeway sound wall!) has proven to be quite effective to reduce standing wave issues.   Within a nominal room listening situation, breaking up a room wall with bookshelves or even shelving with decorative items on them accomplishes much of that task, although that wouldn't be useful in a controlled test environment.  But have yet to see any horizontal shelves as such deployed along freeways; up here in the Bay Area, most soundwall installations tend toward the traditional walls with sporadic decoration.  However, stay tuned -- the project involving widening I-880 in the Hayward/San Leandro area is just winding down; the walls will be the last thing to go up -- and I'm on that freeway at least once per month, so I'll make it a point to check to see what sort of treatment they're applying to the walls and post accordingly.

Thanks for the info. I like the irregular surface treatment and your mention of irregular foam surfaces to reduce sound wave intensity. I wonder if anyone has tried using a spray foam on existing sound walls. It seems like a thin layer of a spray foam (like applying gunite to pool walls) that expands upon impact could significantly reduce highway noise. You're probably right in that it's just not practical.



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