Fix rotation

 map.html

@@ -196,7 +196,8 @@
                        stroke: new ol.style.Stroke({color: color_type, width: 2}),
                        points: 3,
                        radius: 12,
                        rotation: Math.PI * 2.0 * vehicle.heading / 360.0,
                        rotation: Math.PI * parseFloat(vehicle.heading) / 180.0,
                        rotateWithView: true,
                        angle: 0
                    }),
                    text: new ol.style.Text({
@@ -208,6 +209,7 @@
                vehicles_source.addFeature(vehicle_feature);
            } else {
                vehicle_feature.setProperties(vehicle);
                vehicle_feature.getStyle().getImage().setRotation(Math.PI * parseFloat(vehicle.heading) / 180.0);
                if(popup_feature_id == vehicle.id) {
                    popup.setPosition(vehicle_feature.getGeometry().getCoordinates());
                }