Vision Zero
What American & European Cities do well.
US road fatalities have fallen four years in a row. In Sweden, the number of people who died in traffic has been reduced by half since 1997, when Vision Zero started. Here's what the data says works, and where traffic technology helps protect every road user.
No one should be killed or seriously injured in traffic. That's Vision Zero.
The vision has long since crossed the Atlantic. In June 2025, the Vision Zero Academy of Trafikverket (the Swedish Transport Administration) even co-delivered a course with Johns Hopkins University in Washington, DC.
Behind it is one simple fact: people make mistakes. So the road system has to be designed around what people can handle. As Trafikverket puts it, the perfect human does not exist.
Why is Vision Zero so important?
- An estimated 36,640 people died in US traffic crashes in 2025, 6.7% fewer than in 2024, according to the National Highway Traffic Safety Administration (NHTSA).
- San Francisco: traffic deaths down 42% compared with 2024 (SFMTA)
- New York City: down 18% (NYC DOT)
- Washington, DC: deaths more than 50% lower than in each of the two previous years (DC police data)
- Portland: down 32% (PBOT)
- Sweden: about 500 deaths a year when Vision Zero was adopted, 203 in 2025, while traffic grew by 20% over 25 years
The communities seeing results across the US tend to combine several measures: lower speed limits backed by street design, safer crossings, protected bike lanes and retimed signals with Leading Pedestrian Intervals. Then they measure and expand what works.
Side by side, the Swedish and US numbers point to five lessons.
1. Speed Is Still a Deciding Factor
In 2024, speeding was involved in 11,288 US traffic deaths, 29% of the total, according to NHTSA. In Sweden, over half of the traffic on state roads drives faster than the limit. Trafikverket compares a car hitting someone at 50 km/h (about 30 mph) to a fall from the third floor, and recommends 30 km/h (about 19 mph) where cars mix with people walking and cycling.
✅ Where it is already better: On Interstate 465 in Indianapolis, 62 variable speed limit signs help drivers ease off when traffic ahead slows for an incident. In Oslo, speed displays are part of Norway's largest traffic signal operation, 315 signal systems that our teams have maintained since 2003. And in Swansea, Wales, where motorcycles were involved in nearly 16% of road collisions, a sign stays dark until a motorcycle approaches, then shows the rider's speed, with a SLOW warning when it's over the limit.
2. Half of the People Killed Weren't in Cars
That was Sweden in 2025. Cyclists also made up just over half of the seriously injured, and in a typical year, one in six people killed is a pedestrian. In the US, the Governors Highway Safety Association (GHSA) projects 6,732 pedestrian deaths in 2025: the third decline in a row, and still 5% above 2019.
✅ Where it is already safer: Next to two schools in Santa Clarita, California, a pedestrian scramble runs during school hours. All vehicle traffic stops while students and parents cross together, which eliminates conflicts between cars and pedestrians at the crossing. In Sweden, signal priority helps buses through intersections, and the same technology can request the green for cyclists and emergency vehicles through virtual detection, with no physical sensors needed. And in Târgu Mureș, Romania, 12 crossings detect pedestrians and light them up, so drivers see them in the dark and in bad weather.
3. Deaths and Serious Injuries Move Differently
Sweden's deaths fell again in 2025, while serious injuries rose to an estimated 5,000, 5% more than the year before. In some US cities, deaths are falling while serious injuries stay high. Sweden's 2030 targets are at most 133 deaths and 2,800 seriously injured, and the EU aims to halve road deaths and serious injuries by 2030.
✅ Where it is already managed: In Santee, California, adaptive signal control runs on the city's busiest corridor. Its on-demand timing adjustments "have contributed to a measurable reduction in red-light running incidents," says Minjie Mei, the city's principal traffic engineer. In a simulation for an intersection in Køge, Denmark, AI-powered adaptive control cut average delay by 12% in everyday traffic, compared with conventional vehicle-actuated control. After an unexpected routing change, the gap grew to 47% less delay and 39% fewer stops. Less waiting means less pressure to beat the light. US engineering guidelines list cutting unnecessary delay among the countermeasures to red-light running. And at a rural crossroads near Darlington, England, where a serious crash happened in 2023, AI detection now lets a warning sign react to whatever waits at the junction, horses included.
4. Nobody Drives Perfectly
In the US, NHTSA counts 3,208 people killed and an estimated 315,167 injured in 2024 in crashes involving distracted drivers. Reading or sending a text takes a driver's eyes off the road for about 5 seconds. Vision Zero plans for that, so a mistake doesn't end in a death or a serious injury.
✅ Where it already works better: In North America, red light protection extends the red clearance interval when a driver runs a red light, so everyone else's green waits a moment longer. On the A1 near Winterthur, Switzerland, wrong-way drivers are detected automatically and trigger alerts. And when something does happen on Stockholm's highways or in its tunnels, cameras and message signs help manage the incident and inform road users.
5. What Works Gets Scaled
Sweden grew its network of road safety cameras on state roads from 644 in 2006 to about 2,735 at the turn of 2025/2026, and Trafikverket says they save about 20 lives a year. US cities use their own results the same way.
✅ Where it already works: In Gwinnett County, Georgia, adaptive control went live at 11 intersections in May 2025, on the third-party controllers the county had relied on for over a decade. In the county's words, innovation and performance improvements "do not require costly hardware replacements." Scaled up to a whole country, it looks like Norway, where most traffic controllers connect to one traffic management platform. And in Montevideo, Uruguay, a before-and-after study showed 12% shorter travel times and 20% less waiting at intersections. In phase one, 133 intersections went fully adaptive, and around 1,000 are connected today.
Support and funding for North American cities
North American cities can get support and funding to bring Vision Zero closer to reality, and we've put together two guides to help with the applications:
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