Waiting at road kill, or any other carcass is a crap shoot at best. Most likely the predators will come to the carcass at night, and if it's not a large carcass, they will have it cleaned up in one night, or two at the most.
Getting pics. of them with a trail cam. will varfiy for you what time they are coming to the carcass.

If you want action at the drop of a hat, learn to use a predator call and bring them to you when you are ready. Much more effective than sitting at a dead animal carcass and waiting for something that may or may not come while the sun is up.