My two fastest downhills of 44 and 45 were on RAGBRAI, usually the other side of notable hill climb. I’d also nearly matched that in another ride. But in all cases I had a clear clean road to the bottom. Of course the tricky part is looking way in front of you for seams, cracks, debris, etc.
Also last year soon after the 45 mph downhill I guy says, “do you know your back wheel is untrue?”. We were only a few miles out of town so I waited to get into town, then found out my rear rim was cracked in multiple spoke joint locations. I was real lucky that thing didn’t fail on that downhill. So the moral of the story is make darn sure your gear is in good shape as well!