This map shows modeled outdoor noise across Lower Chelsea at 100-meter resolution, combining road, aviation, and rail sources. Green areas measure below 45 dBA. Orange and red exceed the EPA's 55 dBA outdoor threshold linked to long-term health effects. Use the layer toggles to view each source on its own or all together.
What the numbers sound like
- 30 dBAWhisper
- 40 dBASoft rainfall
- 45 dBAQuiet suburban street at night
- 50 dBAQuiet office
- 55 dBAEPA outdoor threshold: light traffic 100 ft away
- 60 dBANormal conversation an arm's length away
- 65 dBABusy restaurant
- 70 dBAHighway traffic 50 ft away
- 80 dBACity bus interior
Population Above the EPA Outdoor Threshold
The EPA's 55 dBA outdoor reference level is a common benchmark for residential noise exposure, especially for activity interference, annoyance, and long-term community noise concerns. About 697 Lower Chelsea residents, or 20.7%, live above that level. By land area, 25.5% of Lower Chelsea is above 55 dBA.
See how noise in Lower Chelsea compares to similar-sized neighborhoods.
Noise by Part of Lower Chelsea
Average noise levels for Lower Chelsea residents, grouped by direction from the center of Lower Chelsea. Northern Lower Chelsea carries the highest population-weighted average; Eastern Lower Chelsea carries the lowest. Just 0% of residents in Eastern Lower Chelsea live in blocks above the EPA's 55 dBA threshold, a fifth of the share in Northern Lower Chelsea.
Central Lower Chelsea
19% of people above 55 dBA
Eastern Lower Chelsea
0% of people above 55 dBA
Northern Lower Chelsea
30% of people above 55 dBA
Western Lower Chelsea
37% of people above 55 dBA
Northern Lower Chelsea sounds about 458% louder than Eastern Lower Chelsea to the human ear, a 24.8 dBA gap. Every 10 dBA roughly doubles perceived loudness. Within any of these directions, two homes a quarter mile apart can still differ by 10 or more dBA depending on how close they sit to a major highway.
How far back from Captain John O'donnell Pkwy do you need to be?
Captain John O'donnell Pkwy produces an estimated 62 dBA at its loudest centerline points. Noise drops logarithmically with distance, with the exact rate depending on what's between you and the road. Tree cover, walls, terrain, and pavement type all matter. At roughly a quarter mile back, traffic fades into the noise level of a soft rainfall.
Calculated from the model's calibrated attenuation formula. About 1% of Lower Chelsea sits under tree canopy (much lighter than most neighborhoods) and roughly 83% is impervious surface like pavement and rooftops. Both are folded into the per-place decay rate above. Heavier canopy pulls noise down faster with distance; impervious surfaces slow the drop.