Just click the green flag to generate an intersection. If only one black line appears, and one of it's end points is the center of the background, it's a dead end. If two black lines appear and form a sort of L shape, the intersection is a turn. If two black lines appear and it looks like one line going through the center of the background, it's a long hall. If three black lines appear, it's a branch-off hall. If four black lines appear, it's two hallways crossing over each other (or a double-branch hall, whatever you want to call it).
Random thing I made for my own purposes, and shared, even though this is probably far from the only tool for doing that and was thrown together in around 20 minutes. This project is designed to simulate hallway intersections, but it also kind of works as maze wall generation. It probably won't work with creating roads, though.