Line-widths and data properties

<!DOCTYPE html>
<html>
<head>
    <meta charset='utf-8' />
    <title></title>
    <meta name='viewport' content='initial-scale=1,maximum-scale=1,user-scalable=no' />
    
    <link href='https://api.tiles.mapbox.com/mapbox-gl-js/v0.29.0/mapbox-gl.css' rel='stylesheet' />
    <script src='https://api.tiles.mapbox.com/mapbox-gl-js/v0.29.0/mapbox-gl.js'></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.4.0/d3.min.js"></script>
    <style>
        body { margin:0; padding:0; }
        #map { position:absolute; top:0; bottom:0; width:100%; }
    </style>
</head>
<body>

style.layers.push({
            id: `tour`,
            source: 'composite',//'stevage.cycletours-5sht4b',
            type: 'line',
            layout: {
                'line-join': 'round'
            },
            paint: {
                'line-color': {
                    property: 'ppl',
                    type: 'exponential',
                    stops: [
                        [1, 'red'],
                        [16, 'blue']
                    ],
                    colorSpace: 'hcl'
                    
                },
                'line-width':{
                    property: 'ppl',
                    type: 'exponential',
                    stops: [
                        [1, 1],
                        [5, 2],
                        [20, 3],
                        [30, 10]
                    ],
                    base: 1
                }
            },
            'source-layer': 'cycletours-5sht4b'

});
        
    
    
    mapboxgl.accessToken = 'pk.eyJ1Ijoic3RldmFnZSIsImEiOiJGcW03aExzIn0.QUkUmTGIO3gGt83HiRIjQw';
    var map = new mapboxgl.Map({
        container: 'map', // container id
        style: style,
        center: [144.97, -37.82], // starting position
        zoom: 9,
        minZoom: 7,
        pitch: 0
    });

map.on('mousemove',e => {
        var features = map.queryRenderedFeatures(e.point, { layers: ['tour'] }); 
        // Change the cursor style as a UI indicator.
        map.getCanvas().style.cursor = (features && features.length) ? 'pointer' : '';
        if (features && features.length) {
            
            console.log(features[0].properties);
        }
    });
});
</script>

</body>
</html>

https://api.tiles.mapbox.com/mapbox-gl-js/v0.29.0/mapbox-gl.js

https://cdnjs.cloudflare.com/ajax/libs/d3/4.4.0/d3.min.js