Noise pollution is a serious problem, and cars make a lot of it. But roads are also a factor.
If everyone, everywhere, got a free electric vehicle at the same time and owners had to travel at very low speeds on well-maintained roads, the world would sound different. But that doesn’t mean it would be quieter. People can have different feelings about the same sound.
As the founder of the Community Noise Lab at Brown University School of Public Health, I am particularly interested in how we humans decide what sound is and what noise is, which is what we call unwanted sounds. We perceive the sounds we experience in our daily life in many ways, from bass to loud. And they can make us feel happy, angry or many things in between.
These feelings can affect our health by relaxing or stressing us. Studies also show that chronic exposure to noise can affect your sleep and hearing and contribute to health problems like heart disease.
How loud are cars?
We know that gasoline-powered cars make a lot of noise, especially on highways where they can travel at high speeds. In 1981, the U.S. Environmental Protection Agency estimated that nearly 100 million people nationwide were exposed to traffic noise every year that was loud enough to be harmful to their health.
At the time, this was about 50% of the U.S. population. Many factors influence how loud a car is on the road, including its design, how fast it travels and physical road conditions. On average, cars moving at around 30 mph on local roads will produce sound levels ranging from 33 to 69 decibels. This is the range between a silent bookcase and a noisy dishwasher.
For cars traveling at typical speeds on the interstate, which is around 70 mph, sound levels reach 89 decibels. It is equivalent to two people yelling their conversation at each other.
Electric and hybrid gas/electric cars emit very low sounds at low speeds because they don’t have internal combustion engines producing noise and vibrations. To ensure that pedestrians will hear electric and hybrid vehicles coming, the National Highway Traffic Safety Administration requires these vehicles to emit sounds ranging from 43 to 64 decibels when they are moving at less than 18.6 mph.
Each manufacturer uses its own warning sounds. At high speeds, there may not be much difference between gas-powered cars and EVs or hybrids. That’s because other factors like tire and wind noise become louder as cars.
Quieter streets for everyone
The infrastructure also contributes to road noise. Cracks, depressions and potholes in the roads can increase the sound levels when cars drive through them. Low-income communities tend to have lower quality roads and highways. So not repairing the roads could literally stifle any improvement in the soundscape of an electric vehicle community.
Another way to reduce traffic noise would be to build more bike lanes and lanes in poorer communities, which often lack them, and to encourage people to replace this cheaper, healthier, cleaner and quieter mode of transport whenever possible.
Electric vehicles are still out of reach for many people because most models cost more than gasoline cars. So in reality, the benefits of switching to electric vehicles, such as lower fuel costs, cleaner air, and somewhat quieter roads, now mainly go to people who live in richer communities and can afford electric vehicles.
That unequal distribution of benefits is what the EPA calls an environmental injustice – a situation where not everyone has the same degree of protection from environmental and health risks.
To share these benefits more equitably, electric vehicles will need to become as affordable as gasoline versions. Many people think of noise as a less urgent nuisance than other more pressing environmental problems, such as air and water pollution. As a result, governments fail to plan, measure, mitigate or regulate noise in any meaningful way.
Noise is a major environmental stressor that negatively affects the health and well-being of all, especially those who are most vulnerable. At the Community Noise Lab, we aim to shed light on the public health implications of noise, support more holistic sound measurements, and study noise alongside other environmental pollutants such as water and air pollution, working together with vulnerable communities in the United States.
Read Also: Column: We’re in a climate crisis. It shouldn’t be this hard to buy an electric car
