It would be nice if u can snap footpaths and cycling paths to roads. Maybe snap more lanes on existing roads. So u can make your own road type. Snapping could be implemented the same way like you can snap 2 or more train tracks in transport Fever 2.
With that mechanic you would also be able to build merging lanes and exit lanes on highways. Wich would make it a lot more realistic.
Thinking about this. The way I would implement is to put a node(snapping point) on every lane and side of a existing road.
For example: a 3-lane Highway would have 5 nodes at then end were you can snap roads to. On the outside nodes you van add lanes, and on the 3 inner nodes you can continue the road by snapping 3 single lane highway for splitting. Or maybe 2 lane + 1 lane highway, etc. Every combination is possible.
Sorry English is not my native language, hope I explained it well enough to understand.