"act_icon").setAttribute("alt", icons[closestFeature.properties.activitytype][1]);
                }

                map.getSource('selectedsource').setData({
                        type: 'FeatureCollection',
                        features: [trackCache.get(closestFeature.properties.id)]
                    }
                );
            }
        });

        map.on('mouseenter', 'tracks-layer', function () {
            map.getCanvas().style.cursor = 'pointer';
        });
        map.on('mouseleave'