Alcohol-impaired driving is the single leading behavioral cause of death in car accidents in the United States. In 2022, 13,524 people were killed in crashes involving alcohol-impaired drivers, accounting for 32% of all traffic fatalities. Speeding is the second leading factor at 29%, and distracted driving rounds out the top three.
Alcohol-Impaired Driving
Nearly one in three fatal crashes involves a driver with a blood alcohol level above the legal limit. That 32% figure has stayed remarkably consistent year over year, making impairment the most persistent and deadly single factor on American roads. The risk spikes at night: alcohol involvement is significantly higher in nighttime crashes, which account for almost half of all passenger vehicle occupant deaths nationwide.
Young drivers are not immune. Among drivers aged 15 to 20 who were killed in crashes in 2020, 29% had been drinking. That number is especially striking given that this entire age group is below the legal drinking age.
Speeding and Its Outsized Role
In 2023, speeding was a contributing factor in 29% of all traffic fatalities. Speed doesn’t just increase your chances of crashing. It makes every crash worse by reducing the time you have to react, increasing the force of impact, and making vehicle safety systems less effective at protecting you.
The problem is especially pronounced among young male drivers. In 2020, 35% of male drivers aged 15 to 20 involved in fatal crashes were speeding, compared to 18% of female drivers in the same age range. Speeding and alcohol often overlap in the same crash, which is one reason both factors show up so prominently in fatal collision data.
Distracted Driving Is Likely Undercounted
Distracted driving is harder to measure than impairment or speed because there’s no breathalyzer for attention. But the available evidence suggests it plays a massive role. Research published in the Canadian Family Physician journal found that driver distraction is responsible for up to 80% of all motor vehicle collisions, not just fatal ones. Cell phone use contributes to more crashes and near-crashes than any other in-car task, including eating or reaching for objects.
One study estimated that texting while driving caused more than 16,000 fatalities in the U.S. between 2001 and 2007 alone. Because a distracted driver who dies in a crash can’t confirm they were on their phone, and because witnesses are often unavailable, official statistics almost certainly underrepresent how many fatal crashes distraction causes.
Not Wearing a Seat Belt
Seat belt non-use isn’t a cause of crashes, but it is a leading cause of death in them. Buckling up in the front seat of a passenger car reduces your risk of fatal injury by 45%. Despite that, a striking number of people killed in crashes aren’t wearing one.
The gap is especially wide among teenagers. In 2020, 56% of teen drivers and passengers aged 16 to 19 who were killed in car crashes were unbuckled at the time. That means more than half of teen crash deaths involved someone who might have survived with a seat belt on. Lower seat belt use is also one of the two major reasons nighttime crashes are so much deadlier than daytime ones, alongside higher alcohol involvement.
Drowsy Driving
Fatigue is another factor that flies under the radar. According to research from the AAA Foundation for Traffic Safety, one in five fatal crashes involves a drowsy driver. Drivers aged 16 to 24 face the highest risk. Like distraction, drowsiness is difficult to confirm after a fatal crash, so the true number is likely higher than what official reports capture.
Drowsy driving mimics impairment in dangerous ways. Reaction times slow, decision-making deteriorates, and in the worst cases, drivers fall asleep entirely. A car traveling at highway speed covers the length of a football field in about three to four seconds of microsleep.
Why Rural Roads Are So Much Deadlier
Where a crash happens matters almost as much as why it happens. Fatal crash rates are more than twice as high on rural roads compared to urban streets, and the injury fatality rate (meaning your chance of dying once a crash occurs) is nearly three times higher in rural areas.
Several factors stack against rural drivers. Roads are more likely to be undivided, increasing the risk of head-on collisions. Roadsides often lack guardrails, so leaving the road means hitting trees, ditches, or poles. And once a crash happens, emergency medical services take longer to arrive, and the nearest trauma center may be far away. Crashes on urban roads happen more frequently per mile of road, but rural crashes kill at a much higher rate.
Nighttime Crashes Combine Multiple Risks
Nearly 49% of passenger vehicle occupant fatalities happen at night, even though far fewer miles are driven after dark. The reasons compound: visibility drops, alcohol involvement climbs, speeding increases, and seat belt use falls. Single-vehicle crashes, where a car runs off the road or hits a fixed object, are also more common at night.
The data paints a clear picture of when fatal crashes peak. A nighttime driver who has been drinking, is speeding, and isn’t wearing a seat belt faces a risk level that is orders of magnitude higher than a sober, belted daytime driver obeying the speed limit. Most fatal crashes don’t involve a single cause. They involve two or three of these factors stacking on top of each other.
Pedestrians Face Rising Risk
Not everyone killed in car accidents is inside a car. In the most recent year of data, drivers struck and killed 7,148 pedestrians in the United States, a number that remains nearly 20% above 2016 levels. One in four of those pedestrian deaths was the result of a hit-and-run crash, and in 94% of fatal hit-and-runs, the striking vehicle was the one that fled the scene.
The rise in pedestrian deaths tracks with the growing size and weight of vehicles on the road, particularly SUVs and trucks, which strike pedestrians at a higher point on the body and transfer more energy on impact. Speed is a critical factor here too: a pedestrian hit at 40 mph is far more likely to die than one hit at 25 mph.