diff --git a/examples/website/collision-filter/app.jsx b/examples/website/collision-filter/app.jsx
index 27bc703e3db..6f9a1a48074 100644
--- a/examples/website/collision-filter/app.jsx
+++ b/examples/website/collision-filter/app.jsx
@@ -6,7 +6,7 @@ import maplibregl from 'maplibre-gl';
 import DeckGL from '@deck.gl/react';
 import {GeoJsonLayer, TextLayer} from '@deck.gl/layers';
 import {CollisionFilterExtension} from '@deck.gl/extensions';
-import * as turf from '@turf/turf';
+import calculateLabels from './calculateLabels';
 
 const DATA_URL =
   'https://raw.githubusercontent.com/visgl/deck.gl-data/master/examples/collision-filter/ne_10_roads_mexico.json';
@@ -14,52 +14,6 @@ const LINE_COLOR = [0, 173, 230];
 
 const initialViewState = {longitude: -100, latitude: 24, zoom: 5, minZoom: 5, maxZoom: 12};
 
-function calculateLabels(data, pointSpacing) {
-  const routes = data.features.filter(d => d.geometry.type !== 'Point');
-  const result = [];
-
-  function addPoint(lineLength, lineString, dAlong, name, priority) {
-    let offset = 1;
-    if (dAlong > 0.5 * lineLength) offset *= -1;
-    const feature = turf.along(lineString, dAlong);
-    const nextFeature = turf.along(lineString, dAlong + offset);
-    const {coordinates} = feature.geometry;
-    const next = nextFeature.geometry.coordinates;
-    if (coordinates[0] === next[0] && coordinates[1] === next[1]) return;
-
-    let angle = 90 - turf.rhumbBearing(coordinates, next);
-    if (Math.abs(angle) > 90) angle += 180;
-
-    result.push({position: coordinates, text: name, priority, angle});
-  }
-
-  // Add points along the lines
-  for (const feature of routes) {
-    const lineLength = Math.floor(turf.lineDistance(feature.geometry));
-    const {name} = feature.properties;
-
-    feature.geometry.coordinates.forEach(c => {
-      const lineString = turf.lineString(c);
-
-      // Add labels to minimize overlaps, pick odd values from each level
-      //        1       <- depth 1
-      //    1   2   3   <- depth 2
-      //  1 2 3 4 5 6 7 <- depth 3
-      let delta = 0.5 * lineLength; // Spacing between points at level
-      let depth = 1;
-      while (delta > pointSpacing) {
-        for (let i = 1; i < 2 ** depth; i += 2) {
-          addPoint(lineLength, lineString, i * delta, name, 100 - depth); // Top levels have highest priority
-        }
-        depth++;
-        delta /= 2;
-      }
-    });
-  }
-
-  return result;
-}
-
 export default function App({
   url = DATA_URL,
   mapStyle = 'https://basemaps.cartocdn.com/gl/dark-matter-nolabels-gl-style/style.json',
diff --git a/examples/website/collision-filter/calculateLabels.js b/examples/website/collision-filter/calculateLabels.js
new file mode 100644
index 00000000000..20a94cb5640
--- /dev/null
+++ b/examples/website/collision-filter/calculateLabels.js
@@ -0,0 +1,48 @@
+import * as turf from '@turf/turf';
+
+/* Utility to add rotated labels along lines and assign collision priorities */
+export default function calculateLabels(data, pointSpacing) {
+  const routes = data.features.filter(d => d.geometry.type !== 'Point');
+  const result = [];
+
+  function addPoint(lineLength, lineString, dAlong, name, priority) {
+    let offset = 1;
+    if (dAlong > 0.5 * lineLength) offset *= -1;
+    const feature = turf.along(lineString, dAlong);
+    const nextFeature = turf.along(lineString, dAlong + offset);
+    const {coordinates} = feature.geometry;
+    const next = nextFeature.geometry.coordinates;
+    if (coordinates[0] === next[0] && coordinates[1] === next[1]) return;
+
+    let angle = 90 - turf.rhumbBearing(coordinates, next);
+    if (Math.abs(angle) > 90) angle += 180;
+
+    result.push({position: coordinates, text: name, priority, angle});
+  }
+
+  // Add points along the lines
+  for (const feature of routes) {
+    const lineLength = Math.floor(turf.lineDistance(feature.geometry));
+    const {name} = feature.properties;
+
+    feature.geometry.coordinates.forEach(c => {
+      const lineString = turf.lineString(c);
+
+      // Add labels to minimize overlaps, pick odd values from each level
+      //        1       <- depth 1
+      //    1   2   3   <- depth 2
+      //  1 2 3 4 5 6 7 <- depth 3
+      let delta = 0.5 * lineLength; // Spacing between points at level
+      let depth = 1;
+      while (delta > pointSpacing) {
+        for (let i = 1; i < 2 ** depth; i += 2) {
+          addPoint(lineLength, lineString, i * delta, name, 100 - depth); // Top levels have highest priority
+        }
+        depth++;
+        delta /= 2;
+      }
+    });
+  }
+
+  return result;
+}