I'm getting my routing from GoogleRoadManager but all maneuverTypes from RoadNodes are 0 so I can't set an appropriate icon for it. can anyone help with this one?
Google Maps Directions API do not provide maneuver types, only textual instructions. So, no way.
BTW, keep in mind that displaying a route provided by Google on a non-Google map (like OSM map) is not allowed by Google T&C.
But you can easily switch to another road manager.