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Drowsy Driving Accidents: Can You Sue a Sleep-Deprived Driver?

drowsy driver car accident
Founding partner of HHJ Trial Attorneys Elliott Jung black and white portrait

Gerry Spence Trial Lawyers College

Adam copy

University of California, Berkeley

Updated: February 24, 2025

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drowsy driver car accident
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While we all know what it feels like to be sleep-deprived, each driver has a level of responsibility to monitor their mental and physical state before operating a vehicle. Severe sleep deprivation can significantly increase the risk of catastrophic accidents, serious injury, and fatalities. This blog discusses what you need to know if you’ve been involved in a collision with a drowsy driver.

Is Drowsy Driving Considered Negligence?

Legally, drowsy driving is classified as negligence because drivers are expected to uphold a duty of care that doesn’t put other road users at risk. Driving while sleep-deprived can be extremely dangerous as it only takes a few seconds to nod off. You can drift into oncoming traffic in as few as three seconds, fail to brake, or miss red lights and stop signs.

A lack of sleep can impact crucial cognitive functions like focus, judgment, and reaction time. These functions are critical in driving safely and making sound decisions on the road. Driving while sleepy is as dangerous as operating a vehicle while intoxicated because it affects your ability to process information.

Even minor delays in reaction can make the difference between braking in time to avoid an accident and rear-ending the car in front of you. The signals between your brain and body slow down, making it incredibly difficult to react to visual input. When a person is extremely sleep-deprived, they experience what is known as microsleep.

A microsleep is an involuntary episode where you slip into unconsciousness. While brief, it can last up to 30 seconds, which, as discussed, is more than enough time for a catastrophic accident. Risky driving behaviors are also more common when a driver is drowsy due to the inability to accurately assess whether a decision is rational.

How Do You Prove a Drowsy Driver Caused the Accident?

If you’ve been injured in an accident with a drowsy driver, it can be difficult to prove. There are no lasting signs of temporary sleep deprivation that can be used as evidence. However, some key elements can be used to make a compelling argument. The following details can play an important supporting role in your case:

  • A lack of skid marks at the scene shows that the driver didn’t react to a sudden stop by braking as a driver trying to avoid a collision would.
  • Some injuries, such as head and neck trauma, may indicate that the driver fell asleep and hit the steering wheel or dashboard while slumped forward.
  • Drug tests showing evidence of medications that cause drowsiness are compelling as they clearly show a potential cause.
  • Vehicle damage focused on one side of a car may indicate that the car drifted to one side before the collision.
  • Some modern cars are equipped with event data recorders that monitor speed, steering, and braking. These instruments can reveal patterns that occurred before a collision.
  • Witnesses who saw the drowsy driver swerving, falling asleep, drifting, speeding, or showing other signs of fatigue can provide critical observational evidence.
  • Post-accident behavior indicates the driver’s state before the accident. Disorientation, confusion, or sleepiness after a crash suggests a lack of sleep.

In addition to the evidence listed, it can be useful to obtain work records that show how many hours the driver spent at work before driving on the day of the accident. If proof of the driver’s schedule shows long work hours or consistently staying up late, it can support your claim.

The driver’s phone records can also provide valuable information. For example, if they were on their phone late at night or sending texts discussing their fatigue, it clearly indicates sleep deprivation. Late-night phone calls, social media posts, and direct messages all have timestamps pointing to how long the driver was awake before the accident.

Do You Need an Attorney to Sue a Drowsy Driver?

Professional representation is not legally required, but there are many benefits to working with an expert. Experienced attorneys have investigation processes that they follow to ensure the collection of adequate evidence. These investigations often rely on expert testimony, accident recreation, and knowing precisely what to look for in police reports.

Working with a car accident attorney gives you access to their entire network of experts and the knowledge they have gained over years of experience. There can be several challenges when you file a claim against a drowsy driver, such as disputes, insurance bad-faith practices, and a lack of evidence. However, having an attorney can help you navigate these challenges and secure the compensation you deserve.

How Can a Lawyer Strengthen Your Drowsy Driving Claim?

A driver aware of their impaired cognition is responsible for taking steps to minimize the risk of falling asleep while driving. Taking a short nap, calling an Uber, or phoning a friend to pick them up is always preferable to driving while sleep-deprived. Drivers who do not take precautions to protect other drivers should be held liable for the harm they cause.

If you’ve been involved in an accident with a drowsy driver, contact HHJ Trial Attorneys for expert legal guidance. Our experienced attorneys will help you pursue compensation to recover the damages caused by a sleep-deprived driver. While these cases can be complex, we will utilize all our knowledge and resources to protect your future and recover fair compensation.

professional attorney and founding partner of HHJ Elliott Jung
Elliot H. Jung

Gerry Spence Trial Lawyers College

Elliot H. Jung is a trial attorney at HHJ Trial Attorneys who focuses on helping injured clients navigate complex personal injury cases. With an emphasis on advocacy, case strategy, and client support, he works to secure fair outcomes for people facing medical bills, lost wages, and other accident-related losses. His approach combines legal experience with a commitment to clear communication and effective representation.

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