Imagine a city the size of Washington D.C. going an entire year without any pedestrians or cyclists being killed on its streets. That’s exactly what happened in Oslo, where officials reported this week that zero pedestrian or cyclist fatalities occurred on the city’s roads in 2019.

City data for the Norwegian capital, which has a population of about 673,000, show a dramatic reduction in traffic fatalities, from 41 deaths in 1975 to a single roadway death last year. One adult man was killed in 2019 when his vehicle struck a fence.

According to a story in the Norwegian paper Aftenposten, safety advocates are directly attributing the virtual elimination of roadway deaths to recent initiatives which have allowed fewer cars into the city’s center.

Over the last five years, the city has taken dramatic steps to reduce vehicular traffic in its downtown, including replacing nearly all on-street parking with bike lanes and sidewalks. Major streets have been closed to cars, and congestion pricing raised the fee to drive into the city center, with the goal of making most of downtown car-free by 2019.

Oslo has not only reduced the number of places where it is possible to drive, the city has also lowered the speed limit, which significantly contributes to a reduction in deaths, said Christoffer Solstad Steen of Trygg Trafikk, a national road safety organization, in an interview with Aftenposten.

Perhaps most remarkably, no children under 15 died in roadway crashes anywhere in the country of Norway during 2019, which has a population of about 5.3 million. In the U.S., car crashes are the leading cause of death for children—about 4,000 children are killed each year in traffic collisions.

One effort cited by Steen that may have contributed to the drop in child deaths are the new “heart zones” drawn around Oslo’s schools, where officials are making physical changes to streets to protect students walking and biking to school, including closing streets to cars during school hours.

Oslo’s news comes as several U.S. cities are reckoning with 2019 figures that show a troubling increase in pedestrian and cyclist fatalities. New York City, Los Angeles, and San Francisco all had more overall traffic deaths in 2019 than in 2018.

New York City’s increase in traffic deaths in 2019 was mostly due to an increase in pedestrian and cyclist deaths. A sweeping plan to add more protected bike lanes as well as more dedicated pedestrian space was approved in late 2019.

In Los Angeles, where more than 239 people were killed on roadways in 2019, the city not only recorded an increase in overall traffic deaths this year, but also marked another year of skyrocketing pedestrian deaths—the number of people killed while on foot has increased 69 percent in five years.

San Francisco exceeded its 2018 fatality count in August of 2019, after several high-profile cyclist deaths prompted city leaders to implement a “quick-build” program that fast-tracked safety improvements.

Some U.S. cities saw glimmers of success in 2019. Washington D.C., where advocates organized a series of major rallies over the last year demanding infrastructural changes to streets, saw the first decline in roadway deaths since 2015. Chicago also saw lower traffic deaths in 2019 than in 2018.

Over the next decade, U.S. cities will start to stare down looming deadlines for their Vision Zero initiatives to eliminate traffic deaths—about 50 cities have set goals to reach zero in the next ten years. Although European cities have seen great success in reducing fatalities, results in the U.S. have been mixed, with few cities achieving sustained reductions year after year.

But some U.S. cities are now experimenting with car-free zones that somewhat mirror Oslo’s policies. New York City’s kicked cars off its hugely successful 14th Street busway and will be implementing congestion pricing to charge a fee for cars to enter Manhattan by the end of the year. Starting January 29, San Francisco’s Market Street, one of its busiest thoroughfares, will be mostly off-limits to private cars.

Progress was also uneven for Oslo in the early years after setting its own Vision Zero goal. But it’s Oslo’s car-free zones that have made the difference, Steen told Aftenposten, because overall roadway deaths haven’t reduced across Norway in recent years the way Oslo’s have plummeted.

However, Oslo hasn’t declared victory for Vision Zero just yet. City officials say that hitting the goal would mean zero roadway injuries—not just zero deaths.

“While we are making great progress, there is still a way to go to consistently keep deaths at zero for all road users,” Anders Hartmann, who works on walking and biking policy for Oslo, said on Twitter.