Noisy traffic might be just as dangerous to public health as traffic accidents, according to a new report from researchers at Chalmers University of Technology in Sweden. Scientific evidence suggests that prolonged exposure to high noise levels are associated with loss of sleep, elevated blood pressure, increased heart rate, and heart attack, not to mention hearing loss.
So how do we make the world a quieter place? We could start by thinking about the acoustics of new buildings and street networks—in effect, making noise reduction part of the city planning process, the researchers say.
Most noise pollution comes from transportation—airplanes, trains, heavy trucks. Even quiet electric vehicles must make some noise, thanks to laws designed to protect pedestrians, especially those with visual impairments. All this adds up to loud cities.
In Berlin, for example, a 2008 noise-mapping study found that 340,000 people were exposed to nighttime noise levels 20 decibels higher than World Health Organization recommendations—less than 55 decibels at night (an air conditioning unit is approximated at 60 decibels) and 65 decibels during the day. At noise levels above those targets, the risk for cardiovascular diseases increases by 20% to 40%, the report states.
So what can urban planners do? According to the study:
- Oriented properly, tall buildings can act as noise shields.
- Lower speed limits (especially at night) and better road surfaces ("quiet pavements") can reduce traffic noise.
- Designing cities to encourage walking and biking cuts down on traffic noise.
- Public transportation should be regulated so that it's at least quieter than the same flow of people using their cars—looking at you, NYC.
"Many of the needed measures are ideal for implementation in dense cities," report author Tor Kihlman said in a press statement. And, he adds, "they are often in line with what is required to tackle climate change."
Read the full report.