Starting with a PDF image of a map copied onto the board, I want to either have lines of a set and unchangeable length that can be dragged onto the board and bent to fit along roads to show a path, or for the freehand pen tool to show the length drawn and/or to stop when a set distance has been reached.

I want to use a map to allow route or network planning with a finite resource, for example design a bus network with x number of buses available. Each line equals a set distance that a bus can travel in a set time. The idea is to link lines to get a longer route, or double up lines to increase the frequency of the buses along the route.

Does anyone know if this is possible?