Why Are Cities So Noisy? And Can We Do Anything About It?
(Source: Unsplash/chairulfajar_.)
Obviously, there’s an aspect of city noise that’s subjective. It’s different for everyone: some folks can’t stand the sound of a lawnmower or leaf blower. Barking dogs are a source of complaint since, well, forever. One of my own pet peeves is the loud sounds of trains coupling, whose noise seems to carry for miles in the dead of night. And a friend once told me they’d never really minded the urban noise, except for one thing: “To me, noise is part and parcel of city life, I even sort of embrace it in some way. But the one thing that I just can’t stand is the sound of the police helicopter overhead.” And then there’s what, statistically speaking, makes up most urban noise: vehicles and traffic.
If different urban noises rub us all the wrong way in different measures, how do we know what’s just personal peccadillo and what’s actually a problem? In other words, how much noise is too much?
In the world of occupational health, there’s long been awareness around the risk of noise-induced hearing loss, and today noise protection is a key part of workplace health and safety. What’s not as advanced is our understanding and awareness about “environmental noise.” That’s the official term the World Health Organization uses for urban noise, and it’s defined as “unwanted or harmful outdoor sound created by human activities, including noise from road, rail, airports and from industrial sites.”
In 2011, the WHO set recommendations for daytime and nighttime environmental noise levels, and found the maximum safe noise level for daytime is 55db (somewhere between moderate rain and normal conversation) and at night, 40db (about the level of a quiet library). Beyond these levels, prolonged exposure to environmental noise has been shown to cause health problems, and not just hearing-related ones.
Until recently, most analysis related to urban noise has focused on noise as an annoyance or disruptor to humans. But with these new guidelines, there was an acknowledgement that too much environmental noise can actually have grave health consequences, noting that “at least one million healthy life years are lost every year from traffic-related noise in the western part of Europe.”
We now know that higher levels of environmental noise raise heart rate and blood pressure, cause harmful sleep interruptions, and are linked to cardiovascular disease, dementia, and cognitive impairment in children, among others. And as with environmental pollution, there are racial and socioeconomic disparities with noise pollution.
In a 2022 report, the United Nations identified urban noise pollution as a top environmental risk (check out the neat interactive feature here).
Me, I love living in a city and I don’t expect it to be totally silent. Maybe you can’t do much about teenagers walking down your street with their music blaring at 2 a.m. But what about the stuff we could do something about, especially when we have research that shows it’s so bad for our health? What could we do to reduce at least some traffic noise?
When I think about this from a Strong Towns perspective, here are a few things that come to mind.
Embrace Nature Solutions
Trees have a powerful sound absorbing effect in cities. Trees planted as noise barriers work better the closer they are to the traffic. (That happens to be where they can capture the most pollution and act as traffic calming devices, too.) Adding trees or extra layers of vegetation alongside traditional noise barrier walls can significantly boost noise reduction. Other vegetation, such as hedges and shrubs, and types of installations, such as green roofs and walls, are effective, too.
As a bonus, nature sounds (rustling leaves, birds, etc.) have a restorative and calming effect, and the visual presence of vegetation counteracts the stress response caused by urban noise. Is there anything trees can’t do?
Allow Multi-Family Everywhere
I heard about someone in my city who moved to a new apartment along a major arterial. It had everything she wanted in terms of building amenities, proximity to transit, and shops and services in walking distance, and it was in the neighborhood she wanted. The one problem was that the traffic noise was so loud that she couldn’t open her windows.
Folks who prefer to or must live somewhere other than a single-family home shouldn’t be relegated to the noisiest areas, but in many places, multi-family housing is only being built along major corridors. By legalizing the next incremental intensity of housing in all neighborhoods, we open up many more housing options and types of urban experiences.
Reduce Vehicle Speeds
Now, of course, we should still do something about traffic noise at the source. And doing that is more achievable than it may seem, because most traffic noise comes from the physical contact of the vehicle on the road, and not the engine. Road noise is a function of vehicle weight and vehicle speed, which means that the heavier and the faster the vehicle is traveling, the more noise it makes.
Lowering traffic speeds has a dramatic effect on noise. Research has found that in urban areas with speeds between 30 and 50 kilometers per hour, a reduction in speed of 10 kilometers per hour reduces noise levels by 40%. In fact, the British Medical Association has stated that, to reduce noise pollution, “the cheapest intervention, and the one with large co-benefits, is speed reduction.”
Improve Walkability
What’s even quieter than a vehicle traveling through the neighbourhood at low speed? Footsteps. Perhaps the broadest but most effective thing we can do is to simply improve walkability; that is, to embrace urban design that enables folks to drive a little less and walk or bike a little more.
Andrew Price’s article on “What Makes a Place Walkable” is a great quick primer on this topic; Jeff Speck’s book Walkable City is an in-depth read if you want to dive deeper. And all the ideas listed above—planting trees, allowing incremental housing, slowing traffic—also help.
City dwellers shouldn’t need to escape to the proverbial “peace and quiet of the countryside” to offset the stressful sound of their everyday life! Urban environments don’t need to be inherently noisy and harmful. There’s great potential to make them calmer and more comfortable places, and what’s really encouraging is that these strategies to reduce noise will do double-duty, helping our places become more financially sustainable at the same time.
Toronto Metropolitan University prof Tor Oiamo sums up this potential beautifully: “I think a day will come when we decide collectively that the city can sound like life.”
Emma Durand-Wood likes walkable cities, front porches, street trees, bumping into neighbors, riding her bike, downtowns, and any excuse to check out a new coffee shop, bakery, or shop. A Winnipegger by choice, she lives in Elmwood with her husband and three children. You can connect with her on Twitter @emmaewood.