diff --git a/debug/routeline.html b/debug/gradient.html
similarity index 58%
rename from debug/routeline.html
rename to debug/gradient.html
index 6b9555a2e42..e9ba78dcdea 100644
--- a/debug/routeline.html
+++ b/debug/gradient.html
@@ -15,7 +15,6 @@
     <div id='map'></div>
 
     <script src='/dist/mapbox-gl-dev.js'></script>
-    <script src='/dist/mapbox-gl-linestring.js'></script>
     <script src='/debug/access_token_generated.js'></script>
     <script>
 
@@ -42,38 +41,35 @@
     map.on('load', () => {
         map.showTileBoundaries = true;
 
-        map.addSourceType('linestring', mapboxgl.LineStringSource, (e) => {
-
-            map.addSource('line', {
-                type: 'linestring',
-                buffer: 0,
-                data: gj
-            });
+        map.addSource('line', {
+            type: 'geojson',
+            lineMetrics: true,
+            data: gj
+        });
 
-            map.addLayer({
-                type: 'line',
-                source: 'line',
-                id: 'line',
-                paint: {
-                    'line-color': 'red',
-                    'line-width': 14,
-                    'line-gradient': [
-                        'interpolate',
-                        ['linear'],
-                        ['line-progress'],
-                        0, "rgba(0, 0, 255, 0)",
-                        0.1, "royalblue",
-                        0.3, "cyan",
-                        0.5, "lime",
-                        0.7, "yellow",
-                        1, "red"
-                    ]
-                },
-                layout: {
-                    'line-cap': 'round',
-                    'line-join': 'round'
-                }
-            });
+        map.addLayer({
+            type: 'line',
+            source: 'line',
+            id: 'line',
+            paint: {
+                'line-color': 'red',
+                'line-width': 14,
+                'line-gradient': [
+                    'interpolate',
+                    ['linear'],
+                    ['line-progress'],
+                    0, "rgba(0, 0, 255, 0)",
+                    0.1, "royalblue",
+                    0.3, "cyan",
+                    0.5, "lime",
+                    0.7, "yellow",
+                    1, "red"
+                ]
+            },
+            layout: {
+                'line-cap': 'round',
+                'line-join': 'round'
+            }
         });
     });
 
diff --git a/flow-typed/style-spec.js b/flow-typed/style-spec.js
index 108a96567f0..dc11a35795a 100644
--- a/flow-typed/style-spec.js
+++ b/flow-typed/style-spec.js
@@ -195,7 +195,8 @@ declare type LineLayerSpecification = {|
         "line-offset"?: DataDrivenPropertyValueSpecification<number>,
         "line-blur"?: DataDrivenPropertyValueSpecification<number>,
         "line-dasharray"?: PropertyValueSpecification<Array<number>>,
-        "line-pattern"?: PropertyValueSpecification<string>
+        "line-pattern"?: PropertyValueSpecification<string>,
+        "line-gradient"?: ExpressionSpecification
     |}
 |}
 
diff --git a/linestring/linestring_source.js b/linestring/linestring_source.js
deleted file mode 100644
index 84a23b30c31..00000000000
--- a/linestring/linestring_source.js
+++ /dev/null
@@ -1,84 +0,0 @@
-const GeoJSONSource = require('../src/source/geojson_source');
-const webworkify = require('webworkify');
-const tilebelt = require('@mapbox/tilebelt');
-
-class LineStringSource extends GeoJSONSource {
-    constructor(id, options, dispatcher, eventedParent) {
-        super(id, options, dispatcher, eventedParent);
-        this.type = 'linestring';
-        const feature = this._data.features[0].geometry;
-
-        this.workerOptions.maxzoom = this.maxzoom.toString();
-        this.workerOptions.covers = {};
-
-        for (let i = this.minzoom; i <= this.maxzoom; i++) {
-            this.workerOptions.covers[i] = getTiles(feature, i);
-        }
-    }
-}
-
-LineStringSource.workerSourceURL = URL.createObjectURL(webworkify(require('./linestring_worker.js'), {bare: true}));
-
-module.exports = LineStringSource;
-
-// extracted from @mapbox/tile-cover and simplified; modified to return
-// duplicates where a line crosses back into a previously visited tile
-function getTiles(geom, zoom) {
-    var coords = geom.coordinates,
-        tiles = [];
-
-    var prevX, prevY;
-
-    for (var i = 0; i < coords.length - 1; i++) {
-        var start = tilebelt.pointToTileFraction(coords[i][0], coords[i][1], zoom),
-            stop = tilebelt.pointToTileFraction(coords[i + 1][0], coords[i + 1][1], zoom),
-            x0 = start[0],
-            y0 = start[1],
-            x1 = stop[0],
-            y1 = stop[1],
-            dx = x1 - x0,
-            dy = y1 - y0;
-
-        if (dy === 0 && dx === 0) continue;
-
-        var sx = dx > 0 ? 1 : -1,
-            sy = dy > 0 ? 1 : -1,
-            x = Math.floor(x0),
-            y = Math.floor(y0),
-            tMaxX = dx === 0 ? Infinity : Math.abs(((dx > 0 ? 1 : 0) + x - x0) / dx),
-            tMaxY = dy === 0 ? Infinity : Math.abs(((dy > 0 ? 1 : 0) + y - y0) / dy),
-            tdx = Math.abs(sx / dx),
-            tdy = Math.abs(sy / dy);
-
-        if (x !== prevX || y !== prevY) {
-            tiles.push([x, y, zoom]);
-            prevX = x;
-            prevY = y;
-        }
-
-        while (tMaxX < 1 || tMaxY < 1) {
-            if (tMaxX < tMaxY) {
-                tMaxX += tdx;
-                x += sx;
-            } else {
-                tMaxY += tdy;
-                y += sy;
-            }
-            tiles.push([x, y, zoom]);
-            prevX = x;
-            prevY = y;
-        }
-    }
-
-    let tileHash = {};
-    for (let i = 0; i < tiles.length; i++) {
-        const id = tiles[i].join('/');
-        if (!tileHash[id]) tileHash[id] = [i];
-        else tileHash[id].push(i);
-    }
-
-    return {
-        order: tiles.map(t => t.join('/')),
-        hash: tileHash
-    };
-}
diff --git a/linestring/linestring_worker.js b/linestring/linestring_worker.js
deleted file mode 100644
index e0cb3dc7aee..00000000000
--- a/linestring/linestring_worker.js
+++ /dev/null
@@ -1,95 +0,0 @@
-const GeoJSONWorkerSource = require('../src/source/geojson_worker_source');
-const Point = require('@mapbox/point-geometry');
-
-class LineStringWorkerSource extends GeoJSONWorkerSource {
-    constructor(actor, layerIndex, loadGeoJSON) {
-        super(actor, layerIndex, loadGeoJSON);
-    }
-
-    loadData(params, callback) {
-        // This happens before any tiles are loaded/parsed by the worker tile
-        // (in GeoJSONWorkerSource, this is where geojson-vt tiles the data)
-        // so we take advantage of this time once the GJ is indexed to precalculate
-        // the total distance, in tile units, of the line feature at each zoom
-        // level, as well the distance before each feature, and inject this
-        // data into the GJ tiles to be used during line bucket parsing.
-        GeoJSONWorkerSource.prototype.loadData.call(this, params, (err, data) => {
-            const gj = this._geoJSONIndexes[params.source];
-
-            for (const z in params.covers) {
-                const cover = params.covers[z];
-                const distanceHash = {};
-
-                let hasFeatures = false;
-                for (const key in cover.hash) {
-                    const zxy = splitKey(key);
-                    const tile = gj.getTile(zxy[0], zxy[1], zxy[2]);
-                    if (!tile || !tile.features.length) continue;
-
-                    while (tile.features[0].geometry.length > 1) {
-                        const next = tile.features[0].geometry[1];
-                        tile.features[0].geometry.splice(1, 1);
-                        tile.features.push(Object.assign({}, tile.features[0], {geometry: [next]}));
-                    }
-
-                    hasFeatures = true;
-
-                    distanceHash[key] = tile.features.map(feature => {
-                        feature.tags = Object.assign({}, feature.tags);
-                        return measure(feature.geometry[0]);
-                    });
-                }
-
-                if (!hasFeatures) continue;
-
-                const distanceOrder = cover.order.map(t => {
-                    if (!distanceHash[t]) {
-                        return 0;
-                    }
-                    return distanceHash[t].shift();
-                });
-                const totalDistance = distanceOrder.reduce((a, b) => { return a + b; }, 0);
-
-                let startDist = 0;
-
-                for (let i = 0; i < cover.order.length; i++) {
-                    const d = distanceOrder[i],
-                        t = cover.order[i],
-                        zxy = splitKey(t);
-                    if (!cover.hash[t].i) cover.hash[t].i = 0;
-
-                    const tile = gj.getTile(zxy[0], zxy[1], zxy[2]);
-                    if (!tile || !tile.features.length) continue;
-                    const tags = tile.features[cover.hash[t].i].tags;
-                    tags.$distance_total = totalDistance;
-                    tags.$distance_start = startDist;
-
-                    cover.hash[t].i++;
-
-                    startDist += d;
-                }
-            }
-
-            callback(err, data);
-        });
-    }
-}
-
-module.exports = function (self) {
-    self.registerWorkerSource('linestring', LineStringWorkerSource)
-}
-
-function splitKey(key) {
-    const xyz = key.split('/').map(i => +i);
-    return [xyz[2], xyz[0], xyz[1]];
-}
-
-function measure(segment) {
-    let distance = 0;
-    const points = segment.map(point => new Point(point[0], point[1]));
-    for (let i = 1; i < points.length; i++) {
-        let prev = points[i - 1], current = points[i];
-        distance += current.dist(prev);
-    }
-    return distance;
-}
diff --git a/package.json b/package.json
index 87a7e16b970..a15e693de6b 100644
--- a/package.json
+++ b/package.json
@@ -156,9 +156,7 @@
     "test-flow-cov": "flow-coverage-report -i 'src/**/*.js' -t html",
     "test-cov": "nyc --require=flow-remove-types/register --reporter=text-summary --reporter=lcov --cache run-s test-unit test-expressions test-query test-render",
     "prepublish": "in-publish && run-s build-dev build-min || not-in-publish",
-    "codegen": "node build/generate-style-code.js && flow-node build/generate-struct-arrays.js",
-    "linestring": "browserify -s mapboxgl.LineStringSource linestring/linestring_source.js > dist/mapbox-gl-linestring.js",
-    "linestring-watch": "watchify -s mapboxgl.LineStringSource linestring/linestring_source.js --outfile dist/mapbox-gl-linestring.js"
+    "codegen": "node build/generate-style-code.js && flow-node build/generate-struct-arrays.js"
   },
   "files": [
     "build/",
diff --git a/src/source/geojson_source.js b/src/source/geojson_source.js
index 064c7655db1..6396f2e3246 100644
--- a/src/source/geojson_source.js
+++ b/src/source/geojson_source.js
@@ -124,7 +124,7 @@ class GeoJSONSource extends Evented implements Source {
                 tolerance: (options.tolerance !== undefined ? options.tolerance : 0.375) * scale,
                 extent: EXTENT,
                 maxZoom: this.maxzoom,
-                lineMetrics: options.lineMetrics
+                lineMetrics: options.lineMetrics || false
             },
             superclusterOptions: {
                 maxZoom: options.clusterMaxZoom !== undefined ?
diff --git a/test/unit/source/geojson_source.test.js b/test/unit/source/geojson_source.test.js
index 5bf8861bfef..4574eaf6544 100644
--- a/test/unit/source/geojson_source.test.js
+++ b/test/unit/source/geojson_source.test.js
@@ -146,7 +146,8 @@ test('GeoJSONSource#update', (t) => {
                     extent: 8192,
                     maxZoom: 10,
                     tolerance: 4,
-                    buffer: 256
+                    buffer: 256,
+                    lineMetrics: false
                 });
                 t.end();
             }
diff --git a/test/unit/style-spec/fixture/layers.output.json b/test/unit/style-spec/fixture/layers.output.json
index e0728f59dd2..210af204e1c 100644
--- a/test/unit/style-spec/fixture/layers.output.json
+++ b/test/unit/style-spec/fixture/layers.output.json
@@ -64,7 +64,11 @@
     "line": 95
   },
   {
-    "message": "layers[15]: layer \"line-gradient-bad\" specifies a line-gradient, which requires a GeoJSON source",
+    "message": "layers[15]: layer \"line-gradient-bad\" specifies a line-gradient, which requires a GeoJSON source with `lineMetrics` enabled.",
     "line": 107
+  },
+  {
+    "message": "layers[16]: layer \"line-gradient-good\" specifies a line-gradient, which requires a GeoJSON source with `lineMetrics` enabled.",
+    "line": 121
   }
-]
+]
\ No newline at end of file