Alcohol Is Involved in 61% of Fatal Crashes at 2 a.m., Distraction Peaks at Noon, and Risk Hours Differ Sharply by Age

America’s 39,254 traffic deaths in 2024 were not driven by any one behavior at any one time, according to a new analysis of NHTSA data from Postman Law. Instead, the study finds three separate daily patterns. Alcohol involvement builds through the night, distraction peaks in the middle of the day, and speeding is common at all hours but most deadly late at night, when it overlaps with drunk driving.

Alcohol plays the largest role after dark. About 30% of 2024 traffic deaths (11,904) involved a driver with a blood alcohol concentration of .08 or higher, and 20.4% involved a driver at .15 or higher. The share of fatal crashes involving alcohol rises steadily through the evening, from 28% at 6 p.m. to a peak of 61% at 2 a.m. Between midnight and 3 a.m., alcohol was involved in an average of 56% of fatal crashes, compared with 12.5% between 9 a.m. and 3 p.m. Speeding was involved in 31% of fatal crashes overall. It rose to 39.7% of overnight crash deaths, compared with 28.1% at midday. Speeding peaks at 40.6% at 2 a.m., the same hour alcohol peaks. Distraction follows a daytime pattern. It is a factor in 8.8% of fatal crashes overall, stays high between 10 a.m. and 3 p.m., peaks at noon (11.6%), and averages about 8% late at night. The study links it mainly to commuting, school runs, and everyday errands.

These behaviors often occur together. Of the 41,912 passenger vehicle drivers involved in fatal crashes in 2024, 43% were impaired, speeding, or not wearing a seat belt. And 1,565 drivers (3.7%), about one in 27, were doing all three at once. Seat belt use adds to the nighttime danger. Among people killed in nighttime crashes, 56% were not wearing a seat belt, compared with 41% of those killed during the day. The combination of alcohol, speed, and no seat belt helps explain why late-night crashes are so often fatal.

Men accounted for 72.3% of traffic deaths (28,385), and women accounted for 10,764. The gap grows after dark: men make up about 75% of deaths between midnight and 3 a.m. and about 68% at midday. By age, 25 to 34-year-olds had the most deaths (6,921), followed by 35 to 44-year-olds (6,252). Together, those two groups account for about a third of all traffic deaths (13,173). People aged 16 to 24 accounted for 16.4% of deaths (6,422), even though they make up a much smaller share of licensed drivers.

The riskiest hour depends on a driver’s age. For 16 to 20-year-olds, the deadliest hour was midnight to 1 a.m., with 215 deaths. Speeding was involved in 47.4% of deaths in that age group, the highest of any group, and alcohol in 31%. Drivers 75 and older were most at risk between 1 p.m. and 2 p.m. (354 deaths), and their crashes had the lowest rates of alcohol (13%) and speeding (14.1%). Alcohol involvement peaks at 41% among 21- to 34-year-olds and falls steadily with age. Distraction stays fairly steady through adulthood and rises among older drivers. Teens also follow their own seasonal pattern. Deaths among 16- to 20-year-olds peaked in June (351), and 30.5% of the year’s teen deaths happened between June and August, compared with 26.6% for all ages. That lines up with the “100 Deadliest Days” between Memorial Day and Labor Day. The behaviors also shift across the year. Alcohol involvement stayed between 29% and 33% and peaked in June. Speeding peaked in May (33.4%) and hit its low in November. Distraction rose to 9.8% of fatal crashes in September, when school starts, and fell to 7.3% in January.

The study also looks at Chicago, which recorded 130 traffic deaths in 2024. May was the city’s deadliest month, with 16 deaths (12% of the year) and the most pedestrian deaths. In 64% of pedestrian deaths, a larger vehicle such as an SUV, pickup truck, or van was involved. Among hit-and-run pedestrian deaths, drivers aged 20 to 30 made up the largest share, in line with national patterns. Right-angle collisions (24%) and turning crashes (21%) caused the most severe crashes, and 14% of fatal crashes happened during rush hour. Most serious crashes were in the Central Business District and on the South and West Sides. Those areas have also seen major safety improvements, including an 18.5% drop in deaths and serious injuries between 2021 and 2024. The study concludes that effective prevention depends on matching the message to the risk: impaired driving and seat belt campaigns late at night, distraction campaigns during the day, and outreach aimed at young drivers in summer.