ase',
                        ['has', 'width'],
                        ['get', 'width'],
                        3 // fallback color if the feature does not have a color property
                    ]
                }
            });

            map.addLayer({
                id: 'mouseover-layer',
                type: 'line',
                source: 'mouseoversource',
                minzoom: 3,
                layout: {
                    'line-join': 'round',
                    'line-cap': 'round'
