This year, Halloween celebrations on a Saturday night coincided with the seasonal time change, creating what some fear were uniquely dangerous conditions on U.S. roads. At the center of the debate is whether abandoning seasonal clock changes would save pedestrian and cyclist lives.
Supporters of ending the twice-yearly change have gained momentum. This summer, the House of Representatives passed the Sunshine Protection Act, which would eliminate fall and winter standard time and keep daylight saving time year-round. For Americans on nine-to-five schedules, that would mean leaving for work in darker conditions on the shortest days of the year in exchange for as much as an extra hour of evening sunlight. The shift would also alter travel patterns in ways that are still being studied. The bill has since stalled in the Senate transportation committee. Its proponents, including President Trump, argue it could encourage outdoor recreation in the evening and narrow the likely window for nighttime crime.
The debate over clocks is tied to transportation history. Standard time arrived in 1883, after railroads linked communities that had observed as many as 144 local times. Those times were standardized into four mainland zones. Daylight saving time was originally intended to conserve energy for indoor lighting during the first and second world wars, but it persisted in some states after the conflicts. The Uniform Time Act of 1966 tried to bring order, yet Hawaii, Arizona and U.S. territories still do not change their clocks, while the other 48 states do. Most U.S. residents say they would prefer to avoid resetting clocks twice a year, though they are divided on which seasonal adjustment to keep.
Research does not settle which approach would be safer. A 2022 study found that not rolling clocks back in winter could save at least 33 human lives and 36,550 deer in car-deer collisions each year, because drivers would have more daylight for evening commutes before deer begin crossing highways. A 2025 study from the Insurance Institute for Highway Safety found that fatal crashes among motor-vehicle occupants fell 7.1% in the five weeks after the fall time change and rose 12% after the spring change. For pedestrians and bicyclists, however, the pattern reversed: their death tolls rose 13% after clocks fell back in the fall and dropped 24% after they sprang forward in the spring.
IIHS researcher Amber Woods said no single variable fully explained the contradiction. For bicyclists and pedestrians, she said, the biggest factor appears to be changing light conditions during key driving periods. Drivers, by contrast, may be more drowsy in the spring after losing an hour of sleep and may drive better in the fall after gaining one. They also may be less inclined to speed on sometimes-icy late fall roads than on dry spring streets after sleeping through an alarm.
Data are not yet available on how the most recent time change affected roadway deaths. The fall change gave Halloween revelers an extra hour to party on a Saturday night, and the holiday is associated with increased drunk driving and phone distraction. Researchers caution that many confounding factors can complicate the picture.
IIHS President David Harkey said the findings would not end the debate. He noted that the benefits for bicyclists and pedestrians are important because fatality numbers for those road users have increased the most over the past decade, but that those gains are largely offset by an increase in crashes in which vehicle occupants were killed.
Vision Zero advocates argue that all road deaths are preventable, so it is not enough to choose the time change that produces the fewest casualties overall, and certainly not to treat people outside cars as sacrificial lambs. They point out that three quarters of pedestrian deaths happen in the dark regardless of what the clock says, and they call for an aggressive, systemic approach. That includes installing streetlights, HAWK signals and other infrastructure to make people outside cars more visible after sunset; redesigning roads and vehicles to slow motorists to less deadly speeds when crashes occur; and limiting distracting cellphone features when drivers are behind the wheel, especially when time changes coincide with major holidays.
Advocates also say the country must confront how car dependency and the suburbanization of poverty reinforce street safety problems after nightfall. They point to late-shift workers traveling home along busy arterials after bus service stops, an unsustainable work culture in which exhausted drivers rush to punch a clock and few have the freedom to travel home at a safer daylight hour, and hit-and-run crashes that spike after dark and disproportionately injure people outside automobiles. They call for more mobility alternatives, including increased nighttime transit service, to break a cycle of unwalkability that leaves many vulnerable road users traveling alone at night.
However the issue is addressed, advocates say the unique dangers of walking and biking after dark need more attention. They argue that ending seasonal time changes will not make a significant difference without broader action to protect people outside cars.
Sources: Streetsblog USA.