It’s also interesting to see the way that the nation is blanketed in a hum of background noise — at least 35 to 50 decibels, or about the sound of a refrigerator humming — from President Dwight D. Eisenhower’s coast-to-coast highway network.
Big swaths of yellow and red bathe most of the country because of road noise, compared with more isolated and concentrated pockets of noise around aviation hubs.
The DOT’s Bureau of Transportation Statistics, in announcing the map’s release to the public for the first time, says more than 97 percent of the U.S. population is generally exposed to no more background noise from aviation or Interstate highways than they would hear from a humming refrigerator. The agency says less than one-tenth of a percent of the population is exposed to 80 decibels or more — which mappers say is comparable to the sound of a garbage disposal.
The agency says the map is intended to make it easier to track trends in transportation-related noise by specific modes of transportation and multiple modes.
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