It is a bit difficult to tell without the context, but it sounds as if this person has been injured and is trying to get up and walk away from the site of his accident. "I groaned" suggests that the person is in pain, "balky steps" would suggest that the person is unsteady on his feet, perhaps staggering because of injury and pain. "Down the cool road, into the fog" seems to be describing the setting. When reading this sentence alone I get a picture in my mind of someone on a lonely highway, on a cold and foggy day who is trying to walk in spite of injuries and great pain.