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What Causes of Car Accidents Are Most Common?

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Early estimates reveal that 16,650 fatal road crashes occurred in the US during the first half of 2020. As for 2019, 36,096 deaths occurred on US roads. The 2019 figures represent a decrease from the previous years up to 2016.

While the downward trend is good news, 16,650 deaths are still 16,650 deaths too many. After all, most causes of car accidents, such as driver errors and car defects, are preventable.

For that reason, knowing what causes road accidents is key to preventing them in the first place.

On that note, we created this guide on the leading culprits behind motor vehicle crashes in the US. Read on to discover what they are so you can prevent putting yourself in the same situation.

Driving While Intoxicated

The most recent data is for 2018, and it shows that driving while intoxicated is the main cause of fatal crashes. Back then, 10,511 deadly crashes involved drivers with a blood alcohol concentration (BAC) of at least 0.08%. Fatalities involving intoxicated drivers accounted for 29% of all road deaths that year.

Operating a vehicle with a BAC of 0.08% is illegal in 49 states. It's only 49, as Utah is the only state where it's illegal to drive with a BAC of 0.05%.

However, driving with a BAC of 0.05% can already raise one's risks for a deadly crash by 7 to 21 times. Even a BAC of under 0.05% can already affect balance and coordination. Having a BAC of between 0.01% and 0.05% can also trigger sleepiness.

All that should be enough reason to avoid alcohol if you plan to drive after. That's because all it takes is two 12-ounce beers for a man weighing 150 pounds to have a BAC of 0.05%. In women who weigh 90 to 100 pounds, a single standard drink can make their BAC skyrocket to 0.08%.

Distracted and Inattentive Driving

In the US, vehicle crashes involving a distracted driver claim the lives of eight people each day. In 2018 alone, driving distractions resulted in over 400,000 people getting injured. Moreover, 20% of distracted driving-related fatalities in 2018 involved people outside of vehicles.

Of that 20%, many were bicyclists, while others were pedestrians.

In any case, distracted driving is operating a vehicle with diverted attention. Anything that makes a motorist lose a tiny percentage of focus on the road can be a distraction. A distraction can be visual, manual, or cognitive.

For this reason, the most dangerous distraction is the use of mobile phones, as it's a mix of all three. Moreover, it's a causal factor in 64% of all car accidents in the US.

Inattentiveness can also be a combination of visual, manual, or cognitive distractions. An example is a driver "lost in thought;" they may be oblivious to the road as they are too absorbed in their thoughts. This may then make them fail to react promptly to changes to their environment.

Delayed reaction times can then make them crash into a vehicle or a pedestrian in front of them.

Improper Crossing of Roadways

Speaking of pedestrians, experts estimate that 3,015 of them died in the first half of 2019. Most of these are a result of traffic crashes, although some are due to non-traffic causes.

Distractions and poor lighting are top car accident causes of cases involving pedestrians. However, others occur due to jaywalking or the improper crossing of roadways.

As such, US states have laws on what to do if you are involved in an accident with a pedestrian who jaywalked. First, give aid to the injured person, and second, prove the pedestrian may also be at-fault for the injury. Depending on the state you live in, drivers may be free of liability based on the pedestrian's fault.

For example, states like Alabama and Virginia have contributory negligence rules. In this case, an injured person's negligence bars them from getting financial recovery. So, a pedestrian who was also partly at fault for the injury won't recovery anything from the driver.

Most other states have comparative negligence rules that divide or "spread" fault. With these laws, the injured pedestrian's fault influences how much they can recover. For example, if a pedestrian was 10% at fault, they can only recover 90% from the at-fault driver.


In 2018, speeding was a causal or contributory factor in more than one in four fatal road accidents in the US. There were 9,378 people killed in crashes involving speeding behaviors. This makes it one of the top causes of deadly traffic incidents in the US.

Some speeding cases don't cause injuries, so they may only lead to minor infractions. However, it can lead to a felony charge if the crash results in severe injuries or deaths.

Drowsy Driving

Every year, at least 100,000 police-reported crashes in the US involve a drowsy driver. Experts also estimate that more than two-thirds of these result in injuries. Worse, such driving behaviors claim more than 1,500 lives.

What's more, drivers don't have to fall asleep behind the wheel to cause an accident. Feeling sleepy is enough to impair their focus, concentration, and reaction times. It's important to learn more about this issue - read the Guide to Avoid Drowsy Driving.

Aggressive or Reckless Driving

In 2018, aggressive and reckless driving were causal factors in 3,706 fatal road accidents in the US. Careless motor vehicle operation either caused or contributed to 2,797 deaths. Negligent and erratic driving behaviors were also implicated in 1,955 deaths.

All these are examples of aggressive and reckless driving behaviors, which endanger others. However, aggressive driving usually involves intentional harassment of other motorists. Reckless driving is any intentional behavior that puts other people in harm's way.

Drive Prudently to Prevent These Top Causes of Car Accidents

As you can see, the chief causes of car accidents have to do with one's own actions or inactions. That's why many experts believe that most motor vehicle accidents are highly preventable. It's also why being a prudent and careful driver can help keep you from causing a crash yourself.

Ready for more safety, health, and travel-related guides like this? Then please feel free to check out our other informative blog posts and resources!

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