地图上只显示蜜蜂线！为什么？

Question

这是我的代码应该告诉我两点之间的路线。

        RoadManager roadManager = new OSRMRoadManager();
        roadManager.addRequestOption("routeType=bicycle");
        ArrayList<GeoPoint> waypoints = new ArrayList<GeoPoint>();
        waypoints.add(gp);
        waypoints.add(new GeoPoint(48.92608,9.13641 )); //end point
        Road road = roadManager.getRoad(waypoints);
        Polyline roadOverlay = RoadManager.buildRoadOverlay(road, this);
        mapView.getOverlays().add(roadOverlay);
        mapView.invalidate();

        Drawable nodeIcon = getResources().getDrawable(R.drawable.marker_node);
        for (int i=0; i<road.mNodes.size(); i++){
                RoadNode node = road.mNodes.get(i);
                Marker nodeMarker = new Marker(mapView);
                nodeMarker.setPosition(node.mLocation);
                nodeMarker.setIcon(nodeIcon);
                nodeMarker.setTitle("Step "+i);
                mapView.getOverlays().add(nodeMarker);
                nodeMarker.setSnippet(node.mInstructions);
                nodeMarker.setSubDescription(Road.getLengthDurationText(node.mLength, node.mDuration));
                Drawable icon = getResources().getDrawable(R.drawable.ic_continue);
                nodeMarker.setImage(icon);                  
                }

但这只显示了蜜蜂线（航空公司）。 为什么我看不到车道的正常路线？