Don't drive drowsy

Don't drive drowsy

DON’T DRIVE DROWSY

TLDR: AVOID DRIVING SLEEP DEPRIVED. IT CAN BE AS DANGEROUS AS DRIVING INTOXICATED. EVEN RUNNING ON 5 TO 7 HOURS OF SLEEP CAN SLOW REACTION TIMES, WEAKEN FOCUS, AND RAISE CRASH RISK. RESEARCH SHOWS FATIGUE IMPAIRS CRITICAL DRIVING ABILITIES LIKE LANE-KEEPING, DECISION-MAKING, AND ATTENTION. PROTECT YOURSELF AND OTHERS BY SPOTTING THE WARNING SIGNS, USING SHORT-TERM FIXES ONLY WHEN NECESSARY, AND ABOVE ALL, PRIORITIZING SLEEP BEFORE GETTING BEHIND THE WHEEL.

WHY YOU SHOULD NEVER DRIVE TIRED

Sleep deprivation leads to measurable deficits in driving ability, including slower reaction times, impaired lane-keeping, increased steering instability, and more frequent driving errors. These impairments are observed in both simulated and real-world driving scenarios, with some studies showing that the effects of sleep deprivation can be as severe — or even worse — than those of alcohol intoxication at legal limits 1,2,3,4,5,6,11,13,14,16,18,19,20. Even partial sleep loss (e.g., 5 to 7 hours of sleep) can increase accident rates and impair attention and vigilance 5,11,14,17.

WHAT DOES THE SCIENCE SAY?

Sleep deprivation affects cognitive functions critical for safe driving, such as attention, working memory, and decision-making. Physiological markers like increased EEG alpha and theta activity, slower saccadic eye movements, and longer blink durations are associated with impaired driving performance 1,3,5,10. These changes reduce a driver's ability to process information and respond to hazards, leading to increased crash risk 1,2,3,16,18,19.

Certain populations take on greater risk when driving sleep-deprived. In particular, young and inexperienced drivers, as well as those with mood disturbances, are particularly vulnerable to the negative effects of sleep deprivation on driving 2,20. There is also evidence of individual variability, with some people more resilient than others, but overall, the risk of impairment is substantial for all drivers 2,10,11,20.

Studies consistently show that sleep deprivation impairs driving abilities. Key impairments include but are not limited to the following:

  • Reaction time: slower responses to hazards 2,3,10,11

  • Lane-keeping: increased deviation and instability 2,4,5,11,13

  • Attention / vigilance: reduced ability to monitor environment 1,3,5,16,18

  • Crash risk: higher rates of accidents and near-misses 2,5,6,14,16

There is strong and consistent evidence that sleep deprivation impairs driving performance, increases accident risk, and affects the cognitive and physiological functions necessary for safe driving. Addressing sleep deprivation is critical for road safety.

HOW TO PROTECT YOURSELF AND OTHERS 

The science is clear: sleep loss can impair driving ability as much as alcohol. However,  understanding the risk is only part of the solution — what matters is knowing how to recognize the warning signs and what to do if sleepiness strikes.

Recognize the warning signs. Drowsy driving rarely announces itself all at once. It often shows up in subtle but dangerous ways: difficulty focusing, heavy eyelids, frequent yawning, drifting out of your lane, or forgetting stretches of the road you just drove. Even brief “microsleeps” — when your head nods for just a second or two — can have fatal consequences at highway speeds. If you notice even one of these signs, you are already too tired to drive safely.

Adopt short-term tactics in emergency situations. If sleepiness does set in while driving, there are temporary strategies that can help you reduce your risk while on the road and reach a safe stopping point:

  • Pull over and take some time to reset: step outside, move around, and breathe fresh air for 10 to 15 minutes.

  • Stay hydrated: even mild dehydration can amplify fatigue, so keep water or an electrolyte beverage within reach.

  • Snack light: avoid heavy, carb-rich meals that may cause glucose spikes and energy crashes.

  • Take a nap: a short 20 minute nap in a safe location can temporarily restore alertness.

  • Selective caffeine usage: coffee or other caffeinated beverages can temporarily boost alertness.

Build better sleep to prevent fatigue. The best defense against drowsy driving starts long before you get behind the wheel. Consistent, high-quality sleep reduces risk and improves performance on the road. Practical steps include:

  • Sleep quantity: getting 7 to 9 hours of sleep each night.

  • Sleep quality: getting sufficient NREM deep sleep and REM dream sleep each night. 

  • Sleep consistency: sticking to a regular sleep schedule, even on weekends.

  • Sleep chronotype: adapting your sleep schedule to your natural sleep preferences (e.g., early bird vs. night owl).

  • External factors: optimize your sleep environment (e.g., cool temperature, dim the lights, and limited noise)

  • Internal factors: adopt pro sleep hygiene behaviours (e.g., avoid alcohol, late-day caffeine, and heavy meals)

The role of employers. Drowsy driving isn’t only an individual issue — it’s also a workplace safety concern. Road accidents often involve people driving to or from work. Employers have a responsibility to create schedules that minimize fatigue, set clear safety policies, and ensure workers never feel pressured to push through exhaustion to meet a deadline.

Take drowsy driving seriously. Although, driving while tired isn’t technically an offence in itself, the consequences can be devastating. A fatal accident caused by fatigue can carry the same penalties as dangerous driving and the stakes are far greater than legal punishment. Ultimately, caffeine, fresh air, or loud music may keep you awake for a short stretch, but only sleep restores your ability to drive safely. Protect your nights, so that your drives during the day are safe. 

SOURCES

  1. Tomson, M., Mathew, T., & Velaga, N. (2025). A systematic review of studies investigating the impact of sleep deprivation on drivers’ physiology and driving performance. Transportation Research Part F: Traffic Psychology and Behaviour. https://doi.org/10.1016/j.trf.2024.12.001.

  2. Lowrie, J., & Brownlow, H. (2020). The impact of sleep deprivation and alcohol on driving: a comparative study. BMC Public Health, 20. https://doi.org/10.1186/s12889-020-09095-5.

  3. Miyata, S., Noda, A., Ozaki, N., Hara, Y., Minoshima, M., Iwamoto, K., Takahashi, M., Iidaka, T., & Koike, Y. (2010). Insufficient sleep impairs driving performance and cognitive function. Neuroscience Letters, 469, 229-233. https://doi.org/10.1016/j.neulet.2009.12.001.

  4. Koopmans, I., Doll, R., Van Der Wall, H., De Kam, M., Groeneveld, G., Cohen, A., & Zuiker, R. (2023). Fit for purpose of on-the-road driving and simulated driving: A randomised crossover study using the effect of sleep deprivation. PLOS ONE, 18. https://doi.org/10.1371/journal.pone.0278300.

  5. Otmani, S., Pébayle, T., Rogé, J., & Muzet, A. (2005). Effect of driving duration and partial sleep deprivation on subsequent alertness and performance of car drivers. Physiology & Behavior, 84, 715-724. https://doi.org/10.1016/j.physbeh.2005.02.021.

  6. Peters, R., Kloeppel, E., Alicandri, E., Fox, J., Thomas, M., Thorne, D., Sing, H., & Balwinski, S. (1995). Effects of Partial and Total Sleep Deprivation on Driving Performance. Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 39, 935 - 935. https://doi.org/10.1177/154193129503901410.

  7. Garjan, G. (2020). P92: Importance of Adequate Sleep Time in Safe Driving. .

  8. Bueno, A. (2002). Sleep Deprivation and Driving Performance. , 14.

  9. Yount, Z., Velasquez, D., Simoneau, L., Lipford, B., Zátopková, K., & Han, H. (2018). 0237 Variations in Driving Behavior Resulting from Altered Emotions and Sleep Deprivation. Sleep, 41. https://doi.org/10.1093/SLEEP/ZSY061.236.

  10. Kwak, S., & Chan, M. (2019). Effect of sleepiness due to complete sleep deprivation on driving performance. Asia-pacific Journal of Multimedia services convergent with Art, Humanities, and Sociology, 9, 615-623. https://doi.org/10.35873/AJMAHS.2019.9.1.062.

  11. Fairclough, S., & Graham, R. (1999). Impairment of Driving Performance Caused by Sleep Deprivation or Alcohol: A Comparative Study. Human Factors: The Journal of Human Factors and Ergonomics Society, 41, 118 - 128. https://doi.org/10.1518/001872099779577336.

  12. Bloomfield, J., Harder, K., & Chihak, B. (2010). The Effect of Sleep Deprivation on Driving Performance. , 20.

  13. Forbes, T., Katz, M., Cullen, J., & Deterline, W. (1958). SLEEP DEPRIVATION EFFECTS ON COMPONENTS OF DRIVING BEHAVIOR. Highway Res Abstracts Hwy Res Board.

  14. Lotfinia, A. (2015). P101: Reduction of Driving Skills by Fatigue Related Sleep Deprivation a Brief Review. .

  15. Bloomfield, J., Harder, K., & Chihak, B. (2005). The driving performance of sleep-deprived commercial motor vehicle drivers. .

  16. Gugerty, L. (2000). Effects of Sleep Deprivation on Driving Accidents and Drivers' Attention Allocation. Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 44, 3-374 - 3-374. https://doi.org/10.1177/154193120004402041.

  17. (2015). Importance of Adequate Sleep Time in Safe Driving Tahere. .

  18. Yegneswaran, B., & Shapiro, C. (2007). Do sleep deprivation and alcohol have the same effects on psychomotor performance?. Journal of psychosomatic research, 63 6, 569-72 . https://doi.org/10.1016/J.JPSYCHORES.2007.06.020.

  19. Makoto, K. (2013). Cognition, Driving, and Sleep. , 145-152. https://doi.org/10.1002/9781118764152.CH14.

  20. Shapiro, C., Bingeliene, A., Yoon, R., & Shahid, A. (2018). Relationship of Quality of Sleep in Adolescents and Young Adults to the Driving Performance. Journal of Sleep Disorders: Treatment and Care, 2018, 1-4. https://doi.org/10.4172/2325-9639.1000208.