The map needs to come before the path - if you create the path without the map you have no way of judging where it stands with respect to other possibilities. However, you only care about the map insofar as it can inform creating the roadmap. So you don’t really care about population density maps or topography if you’re in a car.
What to include or not include in the map is tricky though because you do care about topography if you’re riding a bicycle or walking. This ‘vehicle dependence’ suggests that creating the map and the path needs to be an iterative process.
Map detail is important for seeing path possibilities and path alternative possibilities, however it’s impossible to entirely map possibility space. There is a tension between the fact that you need a map to draw the road but could spend forever creating the map. Perhaps you can resolve this tension by analogy to occupancy maps, where you binarize at each level and only subdivide in places where you know there’s a hit. The first step of roadmapping is frontier mapping.
In a way, science is cartography, engineering is highway engineering. Science describes what is possible, which engineering makes that thing possible. Cycles of Invention and Discovery. By analogy, part of the roadmapping process can be “well we need to send a surveying team here so we know whether we can build over or around that area.”
The map is analogous to some kind of optimization landscape. While I normally like to think of maxima as the place you’re trying to get to in optimization problems, having minima be the places you’re seeking makes more sense with the analogy of a map because then it’s very hard to get over “mountains.”
The map is also isomorphic to the structure of The Idea Maze
The path is a hypothetical traversal of the map to get to a specific point. This definition should suggest how important it is to actually understand where you are starting and where you want to end up.
The path should suggest the answers to the The Heilmeier Catechism and also suggest alternative routes should one be blocked.