Drunk Driving vs. Drowsy Driving – Which is More Dangerous?

When you think about it, this makes a lot of sense. The problems with driving while drunk have to do with slowed reaction times, reduced focus, and poor judgment – all of which are also symptoms of sleep deprivation.

The dangers of drowsy driving

The National Sleep Foundation recently conducted a Sleep in America poll, in which 60% of adults said they drove while drowsy at some point during the last year. According to the AAA Foundation, a third of adults say that they drove despite feeling sleepy during the last month. Even worse, 37% of adults admitted that they’d caught themselves dozing off behind the wheel.

These statistics should be taken just as seriously as drunk driving data, since they also represent significant danger for anyone who shares the roadways with drowsy drivers. While sleep-deprived drivers don’t cause anywhere near as many fatalities as drunk drivers (1,550 each year, compared to around 10,000 each year), many of these deaths are still preventable. Plus, it’s thought that drowsy driving fatalities are actually under-reported, since many law enforcement officers aren’t on the lookout for sleep deprivation as a reason for impaired driving. If someone got six hours of sleep instead of eight, that could definitely be a factor in a traffic accident – but that wouldn’t be likely to get included in any incident report.

Studies have identified an inverse relationship between sleep deprivation and the likelihood of a traffic accident. The less sleep someone gets (including sleep debt built up over several nights), the more likely they are to crash. Even six or seven hours of sleep a night, instead of the recommended eight hours, will double a person’s chances of crashing while driving. With four to five hours of sleep, the risk quadruples; go on the road with less than four hours of sleep, and you’re nearly 12 times more likely to crash.

Is it really fair to compare drunk driving with drowsy driving?

On the one hand, the two things do have a lot of similarities. On the other hand, statistics indicate that drunk driving does cause more accidents and fatalities compared to drowsy driving. However, an Australian study compared intoxication levels and sleep deprivation levels, based on how likely they were to result in a collision. The results were telling: if you stayed awake for 18 hours, the effects would mimic a BAC of .05. This is under the legal limit of .08, but more than enough to impair your ability to drive. Stay awake for 24 hours, and your driving would be similar to someone with a BAC of .10.

What does this mean for the comparison of drunk vs. drowsy driving? For one thing, it demonstrates that they should both be taken seriously. At the same time, though, it’s important to note that it’s much more common to reach a BAC of .10 than it is to stay up for a full 24 hours.

Why drowsy driving can be harder to prevent than drunk driving

As pervasive as drunk driving is, it only takes place after someone has been drinking – usually at night, on holidays, or during weekends. It can occur at any time of day or night, but when you’re looking at individual driving habits, drunk driving has a pretty limited time window when it could happen. Plus, given the success of public awareness campaigns and increased legal penalties for DUIs over the years, people who are intoxicated are more likely to call a friend or a taxi, rather than drive themselves home.

Drowsy driving is different. Not only are many people unaware of the risks, but one night of sleep deprivation will affect them throughout the entire day. Plus, they won’t just be making a trip home from wherever they’ve been drinking; they could take multiple trips in the car per day while drowsy. If they happen to suffer from a sleep disorder such as sleep apnea, the risk of crashing due to drowsiness will be constant. Even if it’s lower compared to someone who’s legally intoxicated, it’s also a round-the-clock problem, which can seldom be said for drunk drivers.

To make matters worse, the solution isn’t as simple as choosing not to drink, or deciding to call a cab. Taking a quick power nap before driving can help a lot, but that isn’t always possible. When it comes to long-term solutions to chronic sleepiness, the answer can be even more difficult to find. If someone is too busy to get eight hours of sleep, or if a health condition lowers the quality of their sleep, it could be impossible to drive in a well-rested state.

Differences in legal consequences of drunk driving vs. drowsy driving

The harm of drunk driving has been well documented over the decades, and every state has their own laws establishing the consequences of a DUI. Where someone lives and their history of DUI incidents will play a factor in their punishment for drunk driving. It is also common to have tougher punishments depending on how many drunk driving incidents a person has had, such as these Mississippi DUI penalties for drunk drivers in the state.
Even though drowsy driving isn’t as strictly punished as drunk driving, don’t think that it gets let off the hook completely. In some states, driving after being awake for 24 hours is classified as the same type of recklessness as driving while intoxicated.

The verdict is pretty clear: if you want to avoid collisions as well as legal consequences, do your best to drive only when you’re alert and sober. This may be hard to accomplish in some cases, but if you set yourself boundaries and stick to them, you’ll be much less likely to do something you’ll regret later on.