Street Noise, Highway Noise

Pedestrians are (obviously) particularly vulnerable to injury and death from cars and trucks, as I've written in the past. But anyone on a street full of gas-powered vehicles also suffers, less obviously, from the constant noise.

A recent series of tweets by Luke Klipp filled me in on some facts:

• The difference between idling and traveling 30MPH is about a 25% increase in decibels. Between idling and 75MPH is an average 75% increase.
• The U.S. Department of Transportation maps noise effects (including airplane noise). Wow. (A snapshot of the map for the Twin Cities, below, shows the effect of airplanes, particularly — those strong red areas are the main flight paths of our airports.)
• Freeways produce a constant amount of sound equivalent to planes landing and taking off. Each of those darkest orange lines on the Twin Cities map is a major highway. These routes are narrower than the airplane areas, but within the surrounding blocks of a highway, the noise is just as intense.

This constant noise has health effects, especially for people who live near highways.

So aside from the public health argument for slowing traffic to protect pedestrians, there's the added argument that the noise is dangerous, and has disparate impact on poorer people (since they are usually the ones who live along the highest traffic through-streets and near urban highways).