This past fall, New York City largely banned cars along its heavily congested 14th street in Manhattan.

It was a moment that seemed to transform the contours of urban life.

“Delivery workers zoomed past unconcerned about getting doored and without interfering with any pedestrians. Two kids rolled by on their skateboards just off the sidewalk instead of weaving in and out of pedestrians. The only disturbance from this peaceful scene was an ambulance screaming by at great speed, something it could not have done a week ago,” wrote Aaron W. Gordon, who wrote New York's Signal Problems subway newsletter and currently works at Motherboard.

New York’s decision is just one example of a larger trend of cities removing cars from their streets.

In cities like New York and San Francisco, this trend has so far amounted to just banning cars from a single street at a time. But other cities, primarily in Europe, have gone further.

Oslo, in Norway, has almost completely banned cars in its city center. Meanwhile, Paris Mayor Anne Hidalgo has been aggressive in ridding the city of cars and making streets friendlier to cyclists. Barcelona is also overhauling its streets to create car-free “superblocks.”

This trend comes at a crucial time. Global climate change, driven by greenhouse gas emissions such as those produced by cars and other vehicles, continues to accelerate at a dangerous pace — and modern modes of transportation are a big reason why.

Globally, about 14% of annual greenhouse gas emissions come from the transportation sector, and 72% of those emissions come from road vehicles, according to the World Resources Institute. In the US in 2017, emissions from transportation accounted for 29% of the country’s total emissions, according to Yale Climate Connections.

Transportation can account for about half of greenhouse gas emissions in cities, Adam Millard-Ball, an Associate Professor of Environmental Studies at UC Santa Cruz, told Global Citizen. In San Francisco, for instance, transportation accounted for 46% of emissions in 2017. Transportation also accounts for nearly half of emissions in Houston.

Interestingly, in New York City, nearly all of the transportation-related greenhouse gas emissions come from on-road traffic, even though less than half of the city’s residents own a car.

Most notably, transportation emissions continue to rise worldwide, at a time when emissions must be reduced.

While companies can make cars that run on electricity rather than greenhouse gas emitting-gasoline, the reality is, as Bloomberg reported last year, Americans — along with the world in general — need to drive less.

Some environmental advocates argue that countries need to enter a post-automobile era in which public transportation surpasses cars as the dominant mode of getting around.

“Cars, generally, have gotten much more fuel-efficient, and therefore less polluting, but there’s just more vehicles and what they call vehicle miles driven,” John Rennie Short, a professor at the University of Maryland-Baltimore County School of Public Policy, told Global Citizen.

“So the efficiencies with the technology have been offset by the increase in the number of cars and the number of miles driven,” he said.

In addition to accelerating climate change, cars also increase air pollution in cities, which leads to higher rates of early mortality and health problems. For example, the heavily-congested New Delhi was the most polluted capital city in the world in 2018 and 2019.

The environmental benefits of reducing cars seems to be immediate. Early results from cities that have taken steps to reduce car use have indicated that these measures are lowering greenhouse gas emissions.

London, for example, instituted a congestion pricing scheme in its inner city for the first time in 2003 — and expanded it in years since — as a way of reducing traffic congestion, but this also caused a 16% reduction in road traffic-related carbon dioxide emissions in the charging zone, according to a 2011 case study from C40.

Milan in Italy has done something similar, instituting congestion pricing in its city center, a program it calls Area C, that has contributed to a carbon dioxide reduction of 35%, according to C40.

But the city of Pontevedra, in northwest Spain, is perhaps the most dramatic example. The city’s mayor, Miguel Anxo Fernández Lores, pedestrianized the city’s center soon after taking office in 1999, according to the Guardian. Carbon dioxide emissions have since declined by 70%.

In general, if an individual commuting a 20-mile round trip were to switch to public transportation, they would lower their carbon footprint by nearly 5,000 miles worth of emissions annually, according to the Center for Energy and Climate Solutions.

There are other benefits to reducing automobile traffic as well. Oslo — where cars have been almost completely banned in the city center — had zero biker or pedestrian fatalities in 2019.  

There are a number of different approaches that cities have taken to reduce car usage, but the most effective approach appears to be putting a price on access into city centers.

“The impact of cordoning off cities or taxing people to come into the cities is really quite dramatic on air pollution” Short said.

Charging access into cities can also generate revenue that can then be put back into public transportation, added UC Santa Cruz's Millard-Ball. London, as an example, has mandated that revenue generated from its program go back into its public transportation system, leading to a sharp increase in bus reliability and causing bus ridership to go up by 38% in the year after congestion pricing was introduced.

But there are complications to implementing restrictions on car usage.

“A more important first step is to stop the policies that are pushing people into their cars,” said Millard-Ball. “Instead of banning something, stop promoting it."

Factors that Millard-Ball said promote driving include engineering requirements for roads that prioritize drivers over pedestrians and cyclists, and requirements for parking spaces in new developments.

Another policy that promotes driving is the artificially low cost of gasoline.

“The amount we pay to fill up a car doesn’t come close to covering both the cost of extracting and refining the gasoline, but also the environmental costs, it doesn’t come close to covering the two of those together,” Millard-Ball said.

Furthermore, according to Short, if a city with low population density and without a well-developed public transportation system implemented a car pricing policy, that could disproportionately impact poorer drivers financially, at least in the short term.

Car ban policies would work best in cities with strong public transportation and high population density, Short said. Unfortunately, public transportation in America is woeful.

London was a good candidate for congestion pricing because it was a high density city, and one where drivers are primarily wealthy.

So in the United States, congestion pricing would be ideal for New York City and San Francisco, but not so much in Los Angeles or Houston, Texas. At least not until these cities revamped their priorities to stop promoting driving, and invest in public transportation.

But for cities like New York, it is long past time to follow the lead of Barcelona, London, and Paris and hit the brakes on car culture — and on climate change.