Last month, Madrid restricted private vehicle access for nonresidents in its city center. A few weeks earlier, London introduced a plan to bar cars from many of the roads in its financial center, continuing its yearslong plan to combat pollution. And Paris, Athens and Mexico City are attempting to ban diesel cars in their city centers by 2025. (In 2016, when Paris banned cars for the day, the city saw a 25 percent decrease in nitrogen dioxide and a 20 percent drop in noise.)

In Oslo, the plan to remove cars from the city began in 2015 when a coalition of progressive political parties called for a city center free from vehicles. Similar plans have been met with resistance in places like Dublin, where local officials have proposed expanding that city’s pedestrian zone, and Barcelona. Even in ecologically minded Oslo, it wasn’t easy.

“There’s been quite a bit of public debate, and there’s been quite a lot of controversy, and it’s been quite difficult to do this in a way that businesses and citizens can accept,” Ms. Marcussen said.

The strongest opposition came from local business owners who were worried that fewer cars would mean fewer customers. So the city came up with a compromise: Instead of an outright ban, they would enact regulations that would allow as few vehicles as possible in the city center. The city designated certain streets for pedestrians or public transit only, restricted the ability of nonresidents to drive through the center, and removed hundreds of parking spots from city streets while creating designated parking spots for disabled citizens and businesses that require a car.

Oslo hopes to be a model for other cities looking to restrict cars in densely populated areas, Ms. Marcussen said, adding that soon enough, the policy will seem obvious.