Can Caffeine Replace Sleep for Drivers?

Coffee and Drowsy Driving accidents
Coffee Cannot Replace the Rest Required for Safe Driving

By Elisabeth Campbell

It’s Monday morning at 6:15 a.m.  The alarm is going off for the fourth time this morning after you’ve hit the snooze three times already.  You know it’s time to get up and face the world, whether you are ready or not.  You stumble through the morning routine of getting ready for work, pour the coffee from your pre-programmed coffee pot into your thermos, and you are out the door.  The drive to work is hazardous, as is any trip down the road, but here in just a few minutes, the caffeine from that first sip of coffee will begin to take effect, and you will be wide awake and alert as you drive.  Maybe you will feel alert, but can caffeine really replace a good night’s sleep for drivers?

The Science and Effect of Caffeine

Caffeine, commonly found in coffee and tea, is the world’s most popular stimulant.  When consumed, caffeine blocks the body’s A1 receptors, which makes the person feel more awake and alert, and caffeine blocks the body’s A2A receptors, increasing dopamine, and causing a stimulating effect.  Simply, caffeine makes the consumer feel more awake and alert, and helps them accomplish tasks more quickly and efficiently.

However, the effects change when caffeine is consumed regularly.  If caffeine is consumed more than about twice per week, the consumer can become addicted and the effects will be lessened.  The effect of feeling more awake and alert does not seem to change over time.  If someone drinks coffee every morning, it will help him feel more alert every morning.  However, the stimulant property of caffeine lessens with tolerance.  The consumer may feel able to accomplish tasks more efficiently, but in reality, he is prone to make more mistakes and possibly cause a collision.

How Caffeine Affects Rested Drivers

An interesting study was done by Utrecht University in the Netherlands, which tested the effects of caffeine on well-rested drivers.  In the study, 24 well-rested people drove on a monotonous highway for two hours, then had a 15-minute break in which they drank coffee.  One group had regular caffeinated coffee, and the other group had decaffeinated coffee.  Then, they drove for another two hours down the monotonous highway.

The results were clear that the group that had the caffeinated coffee objectively drove more steadily than the group with decaffeinated coffee, and the caffeinated group subjectively reported feeling more alert and in control of the vehicle than the group with decaffeinated coffee.  Certainly, the caffeine had a positive stimulating effect.  However, as is seen in the next section, the findings are different for people who are sleep deprived.

How Caffeine Affects Sleep-Deprived People

Another study was done to see how people’s performance compared with caffeine, with a nap, or with neither.  All three groups were trained in an exercise to perform a task during the morning.  In the early afternoon, one group took a 90-minute nap, while the others were doing a relaxing activity (but not allowed to sleep).  After 90 minutes, the nap group was awakened, and the other two groups were given a pill.  One group was given a caffeine pill, and the other group was given a placebo.  Then, the groups were tested on the tasks they had learned in the morning.

As you may have expected, those who took naps did much better than those who used caffeine.  This could be attributed to the finding that sleep increases memory and motor skill function.  However, the very interesting finding in this study was that those who had the placebo outperformed their caffeinated counterparts in the given tasks.  Clearly, the stimulant effect of caffeine was not beneficial to the consumers when they began to feel fatigued in the afternoon.

How Caffeine Affects Sleep-deprived Drivers

It can be deduced from the above study that caffeine is not likely to be helpful for sleep-deprived drivers.  In fact, driving without caffeine at all is probably safer, even if the driver feels sleepier.  The study that follows brings some alarming findings regarding caffeine consumption before driving.

The Institute of Advanced Motorists has said that a study showed that caffeine consumption is dangerous for sleep-deprived drivers.  The positive effects of caffeine on their alertness while driving is very temporary, and when the caffeine begins to wear off, the safety of the motorists’ driving plummets.  Actually, it was said to affect their driving in a way similar to alcohol.

Typically, when consumers begin to feel the effect of caffeine waning, their response is to consume more caffeine.  However, this is not effective.  As was discussed earlier, when caffeine is overconsumed, the consumer feels more alert, but the stimulant property cannot be repeated indefinitely.  In fact, this study showed that using caffeine for only the second time within a few hours did not provide a stimulant effect.

Conclusion

In short, that thermos of coffee in the car on Monday morning is not a good substitute for simply going to bed earlier on Sunday night.  While caffeine has a positive effect on safe driving for rested motorists, it has a significantly negative effect on sleep-deprived drivers.  The true danger in caffeine consumption in conjunction with driving is that drivers think they are more alert and able to drive more safely when they are less equipped to drive safely.

The best remedy for this safety concern is to simply get more sleep.  However, that can be difficult with the busy schedules that so many people have, so it becomes more critical to get the best sleep possible during the few hours that can be devoted to sleep.  A few tips that WebMD gives for making the most of your sleep are:

  • Putting away electronic devices and turning off screens an hour before bed
  • Making the bed as comfortable as possible
  • Keeping the room temperature between 68 and 72 degrees
  • Get regular exercise at least three hours before bed

Following tips like these will make you feel better the next morning, and make your drive to work safer with or without caffeine.

Sources:

Drowsy Driving Guide: Risks and Preventions

NCBI https://www.ncbi.nlm.nih.gov/pubmed/22315048

Autocar https://www.autocar.co.uk/car-news/industry/coffee-can-badly-affect-driving

Bulletproof Musician http://www.bulletproofmusician.com/naps-vs-coffee-which-is-a-better-choice-for-the-sleep-deprived-musician/

Examine.com https://examine.com/nutrition/science-behind-caffeine/

WebMD http://www.webmd.com/a-to-z-guides/discomfort-15/better-sleep/slideshow-sleep-tips