[vetvetdoug]

6pm is dark. Horses are not too good after daylight has gone. A good many accidents with horses and cars involve a)a horse that has no business near a highway b)Horses crossing bridges c)Horses being ridden at night on the road, dirt or paved d)Riderless horses running for what ever reason.

[Ramonan]

Absolutely correct! It gets dark at 4:30.
Tried voluntarily riding after sundown once. Horses got spooky. Things don't look the same to them , even if there is moonlight.

[eno_]

d)Riderless horses running for what ever reason.

One of my very few near-death experiences driving was in my old BMW 2002, on a deserted road in northern New Mexico, almost falling asleep at the wheel, and coming up over a rise to find a horse in the road in front of me.

I hit the brakes so hard, the rear of the car lifted off the road and started to bounce from side to side, with me cranking the wheel opposite the bounce to keep the front pointed forward. Lucky I didn't roll it, which at 80-90mph, would have sucked. I was plenty awake for the rest of the drive.