(For complete code, see MBNaviController.m in the SDKDemo project)
                // real-time navigation
                if (naviMapView == nil) { 
                // Map does not exist
                naviMapView=[[MBMapView alloc]initWithFrame:(0,120.0,kMainScreenSizeWidth, kMainScreenSizeHeight - 120.0 - 55.0)];
                [self.view addSubview:naviMapView];
                // Create a car logo layer
                MBModelOverlay *car = [[MBModelOverlay alloc] initWithFilePath:@"res/red_car.obj"];
                    carHead = MBNaviHeadNorthUp;
                }
                // Initialize the navigation module
                MBNaviSession *naviSession = [MBNaviSession sharedInstance];
                naviSession.enableSound = YES;
                naviSession.delegate = self;
                // Callback function completed by route calculation
                - (void)naviSessionResult:(MBRouteCollection *)routes {
                    // Calculate the road to complete
                    // Get the routes collection, the routeBases in this collection, need to use when initiating navigation to obtain data
                    for (MBOverlay *overlay in naviMapView.overlays) {
                        [naviMapView removeOverlay:overlay];
                    }
                    if (routes.routeBases.count > 0) {
                        MBRouteOverlay *routeOverlay = nil;
                        for (MBRouteBase *base in routes.routeBases) {
                            routeOverlay = [[MBRouteOverlay alloc] initWithRoute:base.getRouteBase];
                            routeOverlay.clickEnable = YES;
                            [naviMapView addOverlay:routeOverlay];      
                        }
                    } 
                }
                - (void)naviSessionTracking:(MBNaviSessionData *)sData {
                    NSLog (@"current car location: %d, %d", sData.carPos.x, sData.carPos.y);
                    NSLog (@"current head orientation: %ld", (long) sData.carOri);
                    NSLog (@"current recommended scale: %ld", (long) sData.suggestedMapScale);
                    NSLog (@" Is there a next turn: %@, and %ld meters turn", sData.hasTurn?@"Yes": @"No", (long)sData.turnIconDistance);
                    NSLog(@"current steering ID: %ld", (long)sData.turnIcon);
                    NSLog (@"Road name after turn: %@", sData.nextRoadName);
                    NSLog (@"current road name: %@", sData.roadName);
                    NSLog(@"\n");
                }