Drivers don’t need to go faster than 20 mph on most city streets.

Last month, a group of families whose loved ones were killed by drivers successfully lobbied the New York state legislature to pass a law allowing New York City to set its own speed limits.

Sammy’s Law allows city officials — rather than the state’s Department of Transportation — to determine the speed limits on their streets with input from community members. The bill will allow the city to drop the speed limit to 20 miles per hour on some streets in an effort to reduce pedestrian deaths.

New York’s not alone in its efforts to lower speed limits. California lawmakers announced new legislation this year to cut speed limits in school zones to 20 mph or less. The city of Oakland also reduced speed limits in several corridors following a new state law that gave local governments the ability to determine speeds on their roads. Washington, DC, reduced the city’s default speed limit — in other words, the speed limit anywhere where there isn’t a sign posted saying otherwise — to 20 miles per hour in 2020, and slowed traffic on major corridors from 30 mph to 25 mph in 2022. These efforts have become especially important in the last few years, as the number of pedestrian deaths in the US has reached a 40-year high.

There’s a reason why cities and states are lowering the speed limit to 20 mph: It’s the speed at which most pedestrians who get hit by a car still have a good chance of survival. Above that, risk rises exponentially: A person hit by a vehicle going 30 miles per hour is 70 percent more likely to be killed than by a car going 25. The average risk of death reaches 50 percent when the driver is going 42 mph, and 90 percent at 58 mph — above that, a pedestrian’s chances of survival get very slim.

There’s a good case to be made that speed limits are too high on city streets. Speeding was a factor in almost a third of all traffic deaths in 2021, and the US has a traffic fatality rate that’s 50 percent higher than it is in other comparable countries in Western Europe, Canada, and Australia.

And there are signs that lowering the speed limit can help. Research shows that cities that reduced speed limits to 20 miles per hour saw a 67 percent reduction in collisions involving children.

Speeding isn’t the only reason why the US has such high road fatality rates. American streets are designed in ways that encourage drivers to go too fast. State departments of transportation typically set speed limits on roads maintained by the state, and the proliferation of roads that are built like highways but still used by lots of people on foot has helped to create the pedestrian fatality crisis. Increasingly, Americans are also driving bigger, heavier vehicles, which are more dangerous to people outside of the vehicle than sedans and other small cars.

Making matters worse, drivers in the United States have gotten more reckless and distracted since the start of the pandemic. A breakdown in traffic enforcement has only contributed to a general sense that there aren’t serious consequences for dangerous driving.

Anyone who’s engaged in activism knows how difficult it is for their efforts to result in meaningful change in public policy. This campaign to get Sammy’s Law passed in New York was no exception. Families for Safe Streets, the organization that pushed for the law, came together in 2014, led by Amy Cohen, whose son, Sammy Cohen Eckstein, was killed by a driver in Brooklyn in 2013. In the year after Sammy was killed, the group successfully lobbied to lower the city’s default speed limit from 30 miles per hour to 25, but the push for the city to lower its speed limits further took years. Despite Gov. Kathy Hochul including Sammy’s Law in her budget, support from the city council, and a hunger strike by Cohen and other mothers last year, the bill was held up by the legislature, thanks to concerns about political backlash from drivers. As a consequence, Sammy’s Law didn’t make it to a vote until this year.

“I’ve come to learn, painfully, that change is slow,” Cohen told Vox in 2022. “Knowing that it could be done so quickly, and we’re not moving quickly enough, is heartbreaking. Every day we are continuously welcoming new members to this horrible, horrible club.”

That year, pedestrian fatalities in the US rose to the highest they’d been in four decades. Other parents, like Jessica Hart, whose daughter Allison was killed by a driver in Washington, DC, in 2021, began speaking out and demanding their local governments do more to ensure safe streets.

Reducing speed limits on city streets is a good first step, but it’s not enough to end the pedestrian fatality crisis on its own. Meaningfully reducing deaths requires redesigning roadways in ways that force drivers to slow down — by reducing the number of lanes, building out curbs and raised crosswalks, or adding bollards and bends to roads.

Lowering the speed limit also doesn’t do much good if people believe they can speed without consequences. In Europe, speed limits are consistently and reliably enforced via speed cameras, resulting in lower traffic deaths. In the US, speed cameras tend to be unpopular both with politicians and the public, in part because no one likes getting a ticket. But investing the funds raised by cameras directly into road safety improvements would help reduce public cynicism that they’re just ripping off drivers.

The automotive industry could make a big difference, too, if it wanted to. Auto manufacturers could put speed governors in cars, something the European Union is requiring of new vehicles beginning this summer, to prevent people from driving at deadly speeds — but the effort has not gained serious traction in the US.

What will ultimately work is likely a combination of several different safety reforms. “It will take a long, sustained effort to change driver behavior if we want to have fewer deaths in this country,” says Michelle May, manager of the Highway Safety Program at Ohio’s Department of Transportation.

But lowering speed limits on city streets is an important first step, one that will likely save lives. And it’s especially meaningful to parents like Cohen and Hart, who are determined that no parent should suffer a loss like they did.

In a video uploaded to X following the passage of Sammy’s Law, Cohen noted that her son would have been 24 this year, near the same age as some of the legislative staff she worked with to get the bill passed. “Sammy would have loved to be a changemaker,” she said. “For him, I will fight for change.”

This post was shared from Vox.