Below are two examples of selecting a waypoint on a zoomed-out map view on a drag-and-drop interface. The expectation on such UIs is that only roads that are visible at that zoom level are considered for matching, and a large
snapRadius would enable that.
The following screenshot shows how waypoint B is matched (default behaviour,
snapRadius is not provided) based on the input coordinates, to the nearest local road, which is not visible on this zoom level.
The following screenshot shows how adding snapRadius changes the matching algorithm. With
snapRadius=1000 waypoint B is matched to the visible 'Federal Motorway 10' road on this zoom level.