I have a shapefile which comprises a number of lines, each representing a bus route. I'm wanting to create a new bus route which is the same as an existing line to a certain point, but then branches off and follows a different route (see image below).
What's the best way to do this?
I'll be doing it numerous times. I'm thinking the best way is to draw a polygon around the parts I want and then clip using the same polygon, and dissolving the result. I don't really want to draw new lines by snapping the vertices to existing routes as each route has thousands of vertices.
I am using QGIS 3.2.3.