The law is that headlights need to light up 300 feet or so ahead of you... GUESS WHERE? YES! In the center of the path ahead of you. And at 60 MPH, it takes a new driver almost 400 feet to stop under ideal conditions.
Re-read that paragraph. Anything odd about that?
Hmm.... So when you’re going 60 MPH down the highway, and 300 feet ahead of you your lights shine on a dead deer in the road, you need 400 feet to stop. The driving experts, who get paid to come up with names for various things, call this "over-driving your lights."
I call it, "being screwed."
The distance you can see ahead of you HAS to affect your speed!
Whether your visibility is reduced because of rain, a dirty windsheild, or because it’s night, NEVER drive at a speed if your stopping distance exceeds your visibility.

And how are you supposed to figure that out? The same way you figure anything else out. Practice. Now that you know to think about it, you’re already WAY ahead of most drivers.
Start out assuming that you CAN stop in the distance you can see, and then see if you can. Find an object - a mailbox, any object - and as soon as you can see it, try to stop. With very little practice, you’ll be able to judge it.