For many, evenings are a time to spend time with friends, run important errands or bring their children to extracurricular activities. Driving at night, though, can be risky. What factors make night driving dangerous?

1. Fatigue

After a long day, drivers may find themselves tired, and that fatigue can put others in danger if those drivers become drowsy or distracted behind the wheel. Because fatigue is more likely for many drivers at night, accidents that result from fatigued driving are also more likely. In fact, drivers can be as much as three times as likely to experience a crash when fatigued.

2. Alcohol

Evenings—especially evenings during the weekend—are often a time when people have a drink with friends, coworkers or family. That alcohol use can result in drunk driving on roadways and inattentive or stumbling pedestrians on sidewalks or in crosswalks.

3. Decreased visibility

While fatigue and alcohol use are factors in many accidents, the Federal Highway Administration notes that decreased visibility is one of the primary reasons for challenges when driving at night. Darkness makes it difficult for drivers to see colors, perceive depth and more. Vehicle headlights’ glare can blind drivers. Headlights often illuminate only a few hundred feet of road, and the limited scope of headlights and streetlights leaves many areas—and potential hazards—concealed in shadows.

Limitations to a driver’s vision can have a significant impact on their driving because, as the National Safety Council points out, vision is the primary source of information for drivers. Anything that impedes that vision impedes their ability to see and respond to hazards.

While night driving may involve a variety of risks, drivers can take steps to protect themselves and their passengers by remaining alert and driving defensively.