How to place a point precisely on two ways without moving one?
Say that I have two ways that cross but do not have a shared point (an intersection). In Potlatch, how can I create a point that is on both ways without moving either one? It seems like no matter how I try to do this I end up creating a junction between the two ways but moving one of them.
This is particularly of interest to me at the moment as I am trying to use the technique described on the [http://wiki.openstreetmap.org/wiki/Roof_modelling roof modelling] page in the wiki to make my roof and parking lot outlines a bit more exact; and I can use "make parallel way" to create a nice grid to work with, but when I try to trace it I have no points to snap to, and when I create the points I end up moving my construction lines. Which then negates the point of doing all that work in the first place.