Turn headlights on
It is dusk, it is raining, traffic is heavy as you leave work and head home, and there is an accident waiting for you along the road.
It comes when least expected, of course- that's what makes it an accident. But unexpected does not mean unpreventable. In this hypothetical case, the accident is caused by a very simple fact. Someone is driving in the half-light and rain without their headlights on.
In Alabama, it is not simply good sense to turn your headlights on the instant you turn your windshield wipers on - it is the law. And like most laws, it was created to protect ourselves from our own oversight and recklessness.
Water diffuses and distorts light - falling water increases that distortion. When it rains, even a light rain, illusions are created and our perceptions change. Driving under these conditions is always hazardous, but driving in these conditions without your headlights increases the hazards exponentially. The harder it rains, the darker it is, the greater the risk of an accident.
The question is not what you can see, but what the other driver can see. Unlike night time driving, in which the headlights are used primarily to light your way, headlights in rainy conditions are used to alert other drivers to your presence.
Some cars, those that are silver, gray, or other pale colors, can blend in with the highway in the rain, making them nearly invisible, not seen by oncoming drivers until it is too late. Headlights increase your visibility and improve your chances of surviving that trip home.
Increase your life span - turn your headlights on.