Mental
When you are wrapped up in thoughts, angry, worried, or upset, your attention won't sufficiently be on the road to preempt or respond to problems. You will make unnecessary mistakes, like passing without checking your blind spot or stomping on the accelerator instead of the brake. You will probably drive similarly to the way you feel — emotionally and illogically.
Preview Physical
Any number of physical problems may also contribute to collisions. Driving while tired or ill can precipitate collisions. In addition to falling asleep at the wheel, your reaction time slows, making rational decisions difficult. Taking medication to combat any of these conditions can further impair your inability to drive alertly and calmly. Consult your doctor while taking medication or after major surgery. Driving when you are physically or mentally unfit is unsafe for both you and others.
Preview Environment
Environmental hazards include everything from potholes in the road to rain, fog, snow, windstorms, black ice, or road construction. Be constantly aware of your environment.
Preview Visual Habits
One common visual habit that contributes to collision avoidance is performing a head check before moving into another lane. Another good habit is looking directly for oncoming traffic or pedestrians when turning right on a red light at an intersection instead of relying solely on your peripheral vision. Wearing needed prescription lenses when driving is also a good habit. Finally, always look before you act — don't just assume the road is clear.