This map shows modeled outdoor noise across 22740 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 60 22740 residents, or 4.7%, live above that level. By land area, 8.2% of 22740 is above 55 dBA.
See how noise in 22740 compares to similar-sized zip codes.
Noise by Part of 22740
Average noise levels for 22740 residents, grouped by direction from the center of 22740. Northern 22740 carries the highest population-weighted average; Southern 22740 carries the lowest. Just 2% of residents in Southern 22740 live in blocks above the EPA's 55 dBA threshold, a third of the share in Northern 22740.
Northern 22740
6% of people above 55 dBA
Southern 22740
2% of people above 55 dBA
Western 22740
2% of people above 55 dBA
Northern 22740 sounds about 35% louder than Southern 22740 to the human ear, a 4.3 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 do you need to be?
produces an estimated 67 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 53% of 22740 sits under tree canopy (much heavier than most zip codes) and roughly 1% 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.