How wakefulness and mood affect your driving
Tiredness, stress and strong emotions impair driving almost as much as alcohol. Fatigue lowers concentration, slows reactions and weakens hazard judgment. Stress narrows attention so you see only parts of the traffic scene. Anger and frustration raise the risk of aggressive choices: tight following, excessive speed, late braking. A safe driver notices these states early and stops or adjusts before it becomes dangerous.
You're responsible for your own fitness to drive the same way you're responsible for the car's condition. If you're too tired to hold attention, too stressed to stay calm, or too emotionally affected to judge traffic — you don't drive. 17 hours of wakefulness equates to about 0,5 promille in driving performance; 24 hours equates to 1,0 promille. Fatigue isn't a soft factor.
You got up at 06:00 after a poor night's sleep. It's now 23:00 and you're driving home from work on a dark country road. You've been awake 17 hours — a 0,5 promille equivalent in driving performance. You yawn and lose focus for 1–2 seconds. At 90 km/h the car covers 25 metres per second — a microsleep of 1–3 seconds can be up to 75 metres without your eyes on the road. Right choice: stop for a 20-minute power nap, or hand over to a passenger.
Many drivers notice fatigue too late. Yawning, heavy eyes, missed road signs, drifting in the lane, and 'no memory of the last few kilometres' are serious warning signs — not minor discomfort. It's also wrong to think loud music or an open window replaces real rest for more than a very short time. A 1–3 second microsleep can cost lives.