I was on my way to work this morning, and it's pouring rain out here in Southern California. While it is day time, the visibility is terrible...
I was driving following a car that I could barely make out in front of me (on the 101 Freeway). The car right next to him was easy to see, as they had their headlights on...
It just seems really stupid. At one point I was driving and there was a group of about 20 or so cars in front of me off a short distance, and NOT ONE OF THEM HAD THEIR HEADLIGHTS ON!!!
For the record: When it's light out, but visibility is bad, turn your headlights on! Don't think "well, it won't help me see any better..." The reason for turning on your headlights is not for you own benefit, but for the benefit of DRIVERS AROUND YOU!!! The #1 explanation given after an accident is "I didn't see him."
Turning your headlights on in bad visibility increases the chance that someone will see you (who otherwise might not) quite significantly!!! And, in bad weather (especially rain), people need all the early warnings they can get, as it becomes difficult to stop on a dime!!!