Nighttime, especially Saturday night and early Sunday morning, is the most hazardous time to drive in Arizona.

During 1990, 47.1 percent of Arizona's fatal accidents occurred between sunset and sunrise.

There are various factors for such tragic statistics, according to researchers at the Arizona Department of Public Safety.

Some drivers exceed the speed limit, drink too much and try to drive home when they are too tired to do so. Then there are those who refuse to drive within the range of their vehicle's headlights.

Research indicates about six percent of this state's fatal traffic accidents occur on either Saturday night or early Sunday morning.

The majority of these accidents occur in clear weather and on dry pavement. So driver error plays a key role in highway death statistics. At DPS, we believe most motorists become more aware of highway safety when darkness diminishes their visibility. But there still are too many drivers who drive too dangerously, especially at nighttime.

Here are some helpful suggestions to safer nighttime driving:

1. Slow down and drive within the range of your vehicle's headlights.

2. Dim your vehicle's headlight beams at least 500 feet ahead of approaching vehicles.

3. Dim the headlights when following another car. Your vehicle's headlights reduce the other driver's vision. In Arizona, headlights must be dimmed when the trailing vehicle is 200 feet or closer.

4. Keep headlights clean. Headlight dirt can cut light output by 75 percent. Proper headlight aim also is very important and should be checked periodically.

5. Never look directly at a glaring headlight. Keep your eyes on the right edge of the road, but at the same time, pay attention to where the oncoming vehicle is by quick glances in that direction.

6. Greatly reduce speed when confronted with oncoming headlights, especially when the headlights are not dimmed. Maintain reduced speed until your eyes are recovered from the glare.

7. Go slow on curves. Remember that your car will not automatically follow the direction of the curve.

8. Avoid using light of any kind in your car while driving.

9. Do not drive if tired. Fatigue reduces your ability to see clearly, and you may fall asleep when least aware of it.

10. Obey the speed limit. Remember that the speed limit is 65 mph only on rural interstates. On state routes and other federal highways the speed limit is still 55 mph.