As a child I had the opportunity to watch them both in real life a lot. Road runners are super cautious, don't go very far from their matrix of holes in the ground and can maneuver 20 times better than a coyote. They accelerate, stop and turn way faster. It takes time for a coyote to get to its top running speed. I've only seen a coyote catch a roadrunner one time out of hundreds of times of watching them try.
Where I lived they always made their nest in a Joshua tree or large cactus where there were lots of Jack rabbits around so they could utilize the rabbit holes.

Ha! Thanks for ruining it for all of us.

Happy friday, kate