IIRC, this won't help you, but when I had my bike I never felt comfortable above 35-40mph.
Of course cycling is a risk as well as riding at night, and going above that speed presents one as well. It never stopped me from hitting 70mph on the interstates, but I would try to stick near 'safe' drivers and use their auto's superior lighting system.
You just ever be too safe about a deer corpse or a shredded tractor tire in the middle of the road.
I've had one night encounter with an object in 40,000 miles. It was between Vegas and Pahrump going up a hill through a curve. Somehow, when cornering the beam hits the ground at a better angle and you can see better. Well, I was headed straight to this old tire and adjusted with a second or two to spare.
Cycling is an excellent cross trainer for driving a car. You become more courtious and aware of your surrounding, and see exits and escape routes and stuff.