AUTONEWS

Car‑free streets reduce noise and air pollution. More cities should have them

Every summer, cities around the world host car-free days and temporarily pedestrianize streets. Following their success elsewhere in the world, temporary pedestrianized streets are becoming more common in North America, such as for large sporting events, cultural festivals and farmers’ markets.

This year, as part of the FIFA World Cup, some cities in North America created pedestrianized fan zones for spectators and visitors. In Vancouver, the city pedestrianized a large stretch of Granville St. in the downtown core.

Doing so can help support local businesses, give public spaces back to people and retrieve them from cars. The City of Vancouver recently announced that Granville St. will remain pedestrianized until at least September.

Pedestrianized streets emerged in Europe more than seven decades ago. The two most notable precedents are Lijnbaan in Rotterdam and Strøget in Copenhagen. Despite apprehension from some business owners and a minority of drivers, many success stories have put those concerns to rest while often exceeding expectations.

These streets have proven to be major draws for pedestrians and cyclists, yielding increased economic activity without needing to inefficiently devote public spaces to private vehicles. Critics often worry that pedestrianization simply shifts traffic elsewhere. While the effects depend on local design, many cities have found that some trips disappear altogether as people switch routes, travel modes or destinations.

Pedestrianized streets are often evaluated economically, but their health benefits receive far less attention. Our recent study at Carleton University measured air and noise pollution experienced by people walking and cycling along Ottawa’s Queen Elizabeth Driveway (QED), with and without the presence of vehicles.

The QED is part of the National Capital Commission’s Bikedays program, which temporarily provides long stretches of its scenic roads to people on foot and bike. The program dates back to 1970, making it a pioneer.

However, despite extended hours during the COVID-19 era when downtown residents otherwise lacked recreational space and the adjacent pathways were overcrowded, the hours have since become restricted to daylight hours on weekends.

The QED presents a particularly enticing research opportunity because the roadway is exclusively open to pedestrians and cyclists on certain weekend hours in the summer. Accordingly, a near-perfect natural experiment allows the impact of vehicles to be measured.

We measured particulate matter and ultrafine particles (both of which are produced by cars and have numerous health consequences) and noise at 12 measurement stations along the roadway.

Traffic noise is not just the most annoying source of noise in cities; it’s affecting long-term health. Measurements along the QED from a combination of weekdays and weekends and at three times per day showed that air pollution was typically about 70 per cent higher when cars are present, while perceptible noise was about 50 per cent higher.

The presence of this noise may make the difference between being able to have a comfortable conversation and having to shout and strain to listen. Similar results were found in other studies, such as New York City’s Highline, which is an above-ground railway that has been converted to a pedestrian pathway.

Researchers found noise and air pollution were almost 40 per cent lower on the Highline relative to the street level. The impact of pollution and noise is particularly acute for stationary road users, such as diners at patios, who cannot easily move out of harm’s way.

The future of pedestrianization...Some might think that new technologies like electric vehicles will absolve vehicles of noise pollution. However, EV noise can approach the level of gas-powered vehicles — especially above about 50 kilometres an hour — due to tire noise, air turbulence and horns. And while EVs eliminate tailpipe emissions, their heavier weight results in greater tire-related particulate emissions.

The health and safety benefits of pedestrianized streets extend well beyond air pollution and noise. Without vehicles, collisions with people are virtually eliminated.

In 2023, one-quarter of the 1.2 million global road traffic deaths were pedestrians and cyclists who died after being hit by drivers. Not only are those deaths tragic, but the perceived risks prevent people from taking up cycling.

There are numerous physical and mental health benefits to walking and cycling. Ensuring that our cities have ample, pleasant and safe spaces to do so, particularly with access to amenities, would be a critical step forward for public health.

As YouTuber Jason Slaughter of the channel Not Just Bikes once said: “Cities aren’t loud; cars are loud.”

While the implementation details of pedestrianization are important, uncertainty should not be feared. Pedestrianized streets benefit people, businesses and the planet. It’s time to rethink our cities, especially the most car-centric ones.

A city for people, not machines...Cars are one of the primary sources of air pollution in urban areas. According to the European Environment Agency (EEA), road transport accounts for about 30% of CO2 emissions in EU cities. Road traffic causes suspended particulate matter (PM2.5 and PM10) to significantly exceed WHO standards in metropolises like Warsaw or Krakow. Conversely, air quality is noticeably better in places that restrict vehicle access, such as Copenhagen or Amsterdam. In the Danish capital, for example, a staggering 62% of residents choose to commute to work by bike. The concentration of PM2.5 there is lower than in cities of similar size dominated by cars.

Fewer cars also mean less noise. The World Health Organization estimates that street noise in large cities can cause stress, sleep disorders, and even increase the risk of heart disease. In the Dutch city of Groningen, the city center is almost entirely closed to cars. According to urban planners, noise levels there have dropped significantly compared to the 1970s, which corresponds to the subjective feeling of an environment being “twice as quiet.”

Space reclaimed, space secured...Cars occupy vast areas of our cities. In Los Angeles, where car culture is deeply rooted, parking lots and roads take up as much as 70% of the downtown area. In cities like Utrecht in the Netherlands, which prioritize cyclists and pedestrians, this space is being reclaimed for parks, squares, and cafes. Utrecht revitalized its city canals, removing parking lots in favor of boulevards and bike paths. The result? An increase in tourism and higher resident satisfaction with the quality of life.

Reducing car traffic also decreases the number of accidents. In the Netherlands, where cycling infrastructure is exemplary, the number of fatal road accidents per capita is one of the lowest in Europe—3.8 per 100,000 people in 2023, compared to 5.1 in Poland. Car-free cities also promote inclusivity—pedestrians, people with disabilities, and children gain a safer environment.

Proponents of car-free cities point to the growth of the sharing economy—from city bikes to car-sharing. In Paris, the Vélib’ city bike system records up to 300,000 trips a day. Meanwhile, Low Emission Zones (LEZ) reduced car traffic in the center of the French capital by 20% between 2015 and 2022. Such solutions help reduce the demand for cars and lower vehicle maintenance costs for residents. “The future of cities is not cars, but people. Streets should be meeting places, not parking lots”—this is one of the mottos of Anne Hidalgo. The Mayor of Paris has introduced an ambitious plan to restrict car traffic by 2030.

In the German city of Freiburg, the Vauban district was designed around the idea of car-free cities. Residents park their cars on the outskirts, and 70% of trips are made on foot or by bike. The result? As many as 80% of residents declare that their quality of life has improved. However, real estate prices in the increasingly popular district have also risen—by 25%.

Spanish Pontevedra is an example of a radical approach. Since 1999, the city center has been closed to cars, which reduced CO2 emissions by 67% and road accidents by 90%. The cost? Rebuilding streets and social campaigns cost €20 million. The city gained, but lost some businesses dependent on customer access by car.

In Singapore, the Electronic Road Pricing (ERP) system reduced traffic by 24% but raised living costs for drivers by 10–15% annually.

The Netherlands is the model for a bike-friendly city. In Amsterdam, 38% of trips are made by bike, and the city invested €600 million in cycling infrastructure between 2010 and 2020. The result? An 11% drop in CO2 emissions and 30% fewer road accidents in the center according to city reports. However, the Dutch model required decades of planning and a shift in mentality. The latter cannot be achieved everywhere in a short time.

Carleton University