dragging a via point outside the covered area confuses osrm: the route will now go in a straight line from start to end.

http://localhost:5000/viaroute&start=55.663756828524,12.603463646287&dest=55.657390044536,12.593163963674&via=55.66027,12.62801&z=15&output=json&jsonp=showResultsRoute&geomformat=cmp&instructions=true