New Bayshore Sound Wall Palo Alto Issues, posted by Dick, a resident of the Palo Verde neighborhood, on Apr 18, 2007 at 5:29 pm
The new 14-foot-high, 800-foot-long sound wall along Bayshore at the end of Loma Verde will undoubtedly reduce the noise level at the site of the new condominiums, but I wonder what effects it will have on the residents further away from Bayshore.
The sound patterns from similar walls have resulted in much greater noise levels at some locations. Has this been studied for this wall? The Weekly's article centered on how the wall is to be painted, but the noise issue could be of much greater concern.
Posted by don't worry, be happy, a resident of the Midtown neighborhood, on Apr 18, 2007 at 7:18 pm
It's an interesting question. I spent a few minutes googling, and the closest to an emperical study that I could find was a 2002 science fair project that took various sound meter measurements at various distances from sound walls.
The basic conclusion appeared to be that one wall reduced db over no wall for those on the quiet side. The noisy side across the freeway, however, experienced significant reflected noise.
In our case, that's out towards the baylands.
The interesting case was two parallel sound walls. Due to the reflections and dispersion, the sound between 250-500 feet was noiser than no wall at all.
I think the conclusion is that unless you plan to live east of the wall, or Caltrans gets the crazy idea of lining both sides in this section, you'll be better off.
Posted by The Walled City, a resident of Another Palo Alto neighborhood, on Apr 19, 2007 at 2:03 am
1. Soundwalls reflect sound across the other side of the freeway as stated by DWBH. They may also increase sound volumes some distance away from the freeway, but that might be an effect of double sound walls (both sides of freeway).
2. There's a proposal to widen 101 between highway 84 and highway 85, and that might mean soundwalls for the length of Palo Alto.
3. My preference would be no art, just complete coverage with foliage. Foliage is most effective at reducing the reflections of sound from a soundwall.