less than a 1000 feet
Your headlights should be on whenever it will make a difference on the road. If you can look at the road and be able to tell that your headlights are on/off, then they should be on. Some states, such as New York, require headlights to be on when visibility is limited, such as in rain or fog, even in the day, regardless of whether or not you can see them on the road. In fact, one of the criteria for headlights is whether or not you are using your windshield wipers. At dusk or, in some states where mandated, when it is raining or foggy and you need to turn on your windshield wipers.
If daytime visibility is poor but not seriously reduced, you should switch on your low-beam headlights. This will help increase your visibility to other drivers and make it easier for them to see you.
Headlights should be on at least 30 minutes after sunset and can be off 30 minutes before sunrise. They should also be on during times of limited visibility, such as in rain or when it is snowing.
Your headlights should be on whenever it will make a difference on the road. If you can look at the road and be able to tell that your headlights are on/off, then they should be on. Some states, such as New York, require headlights to be on when visibility is limited, such as in rain or fog, even in the day, regardless of whether or not you can see them on the road. In fact, one of the criteria for headlights is whether or not you are using your windshield wipers. At dusk or, in some states where mandated, when it is raining or foggy and you need to turn on your windshield wipers.
reduced visibility and you don't want to outrun your headlights
Yes. They should always be on for safety.
Give-way to the starboard side
Unless you have someone else directing you.
Because the light can reduce visibility and reflect back into the driver's eyes as heavy rain, fog or snow falls.
In order to ensure your visibility, keep your windshield and exterior light covers clean and make sure your wipers and defrosters are working properly. You should use your headlights whenever driving in rain, fog, or snow, but remember to use only your low-beam lights, as high beams can actually impair your visibility.
How far should headlights shine?
Any time after six o clock Laws will vary a bit between jurisdictions, but this version from the State Of New Jersey is pretty common; "Proper use of headlights is critical to safe driving. Headlights must be used between one-half hour after sunset and one-half hour before sunrise. Headlights must also be used when visibility is 500 feet or less, when using windshield wipers (during rain, snow and ice) or when encountering fog, mist, smoke or other factors that reduce visibility." Note that many semi trucks will use their headlights 24/7. It's a safety issue. Being seen is important.