There's planning that happens there, where one casts one's eye along the length of visible road, somewhere between steering the car and consulting the map.
Well, I do sort of do have a couple of intermediate like steps. But I usually do them after the novel level and scene level sketches. I use Dan Well's seven point plot structure to plan out each subplot for the characters that have them, which for me is below the novel level but above the scene level. And then just right before I write the scene, I do an in-depth outline of that scene in point form, not just listing what happens but things to keep in mind like theme and what subplots get weaved in and advanced. Now as I'm actually writing the scene out, I may find I can't fit everything I want in, so those things I miss may get pushed ahead into the next scene or the scene after that. OR I might have to go back and redesign/rethink the scene to fit stuff in.