Driving at Night

Driving at night presents different challenges from driving during the day. At night, sight distance is limited, and drivers do not have the advantage of color and contrast that is available during daylight hours. The risk of a crash at night is about 40 percent higher than during the day.

Three factors affect night vision: the ability to see under conditions of low light, the ability to see against glare, and the time needed to recover from glare. As we age, our abilities to see with and recover from oncoming glare diminishes and our field of view decreases, making it more difficult to drive at night.

Seeing clearly during the day doesn’t necessarily mean seeing clearly at night. Eyes must constantly adapt from brightly lit areas to areas of darkness. But as we get older, this ability to focus and adjust to varying lights diminishes as the eye muscles become less elastic.

To improve the ability to see and drive at night, here are a few techniques and tips:

Keep your eyes moving. Search the dark areas ahead and to the sides. Look for flashes of light at hilltops, curves, and intersections that may indicate the headlights of other vehicles.
Keep all windows and headlights clean. Dirty windows can increase glare and make it more difficult to see. Dirty headlights can reduce efficiency by as much as 90 percent.
Use headlights wisely. Use high beams whenever possible, but return to low beams when following or meeting oncoming vehicles.
Don’t tint your windows as it reduces visibility. Today, many vehicles have sun-block tinting as standard equipment.
Protect your eyes from glare during the day. Wear good sunglasses on bright days. Prolonged exposure of your eyes to the sun can temporarily ruin your night vision. Rest a while after steady daytime driving before driving at night.
When approaching a vehicle with its high-beam headlights on, don’t retaliate by flashing and leaving your high beams on. This will only increase the chance that two drivers cannot see. Look to the right edge of the roadway, and use the white pavement line to help guide you past the glare.
Driving on well-lit roads can also help reduce glare recovery time. It takes most drivers only a few seconds to recover, but recovery times increase as people age. It’s common for some drivers to take as long as five to 10 seconds to recover from glare. This can mean a driver experiencing oncoming glare may travel 400 to 800 feet at 55 mph without full visibility.
Increase your following distance, as it is more difficult to find potential problems on and along the roadway, and give yourself more time to respond by increasing your following distance by four to five seconds.
Make it easier for others to see you. Be sure all the exterior vehicle lights work properly. In case of a vehicle breakdown, pull completely off the roadway beyond the end of the guardrail, if possible, and turn on the emergency flashers.

If any of the above tips or techniques do not improve your ability to see, visit your ophthalmologist.

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Published in the January/February 2002 issue of the AAA Traveler.