Logically, if you have the spot lights pointed down the road they do NOTHING to illuminate anything coming at you from a 90 degree angle.
It would seem that floodlights would be the logical choice. However...
The factory driving lights on my truck put out a wide low (flood) light directly ahead of the vehicle. They too do NOTHING to illuminate anything coming at me from the side of the road until it is too late.
Flood lights would have to be so bright and obnoxious to give you any chance of seeing anything far enough ahead to stop in time, that they would be virtually unusable if there is any oncoming traffic at all. You would be constantly turning them on and off to avoid blinding oncoming traffic.
I live out in the sticks and there is so much traffic that even just using the factory brights is pointless. You can not see a car for miles but the moment you click on the brights, BAM, here comes a car.