JavaScript Maps SDK

Measure distances

Click points on a map to create lines that measure distances using turf.length. 


<!doctype html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <title>Measure distances</title>
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <link rel="stylesheet" href="https://maps-sdk.trimblemaps.com/v4/trimblemaps-4.2.5.css" />
    <script src="https://maps-sdk.trimblemaps.com/v4/trimblemaps-4.2.5.js"></script>
    <style>
      body {
        margin: 0;
        padding: 0;
      }
      html,
      body,
      #map {
        height: 100%;
      }
       .distance-container {
        position: absolute;
        top: 10px;
        left: 10px;
        z-index: 1;
      }

      .distance-container > * {
        background-color: rgba(0, 0, 0, 0.5);
        color: #fff;
        font-size: 11px;
        line-height: 18px;
        display: block;
        margin: 0;
        padding: 5px 10px;
        border-radius: 3px;
      }
    </style>
  </head>
  <body>
    <div id="map"></div>
    <div id="distance" class="distance-container"></div>
    <script src="https://npmcdn.com/@turf/turf@5.1.6/turf.min.js"></script>
    <script>
      TrimbleMaps.setAPIKey('YOUR_API_KEY_HERE');

      const map = new TrimbleMaps.Map({
        container: 'map',
        style: TrimbleMaps.Common.Style.TRANSPORTATION,
        center: [2.3399, 48.8555],
        zoom: 12,
      });

      const distanceContainer = document.getElementById('distance');

      // GeoJSON object to hold our measurement features
      const geojson = {
        type: 'FeatureCollection',
        features: [],
      };

      // Used to draw a line between points
      const linestring = {
        type: 'Feature',
        geometry: {
          type: 'LineString',
          coordinates: [],
        },
      };

      map.once('load', () => {
        map.addSource('geojson', {
          type: 'geojson',
          data: geojson,
        });

        // Add styles to the map
        map.addLayer({
          id: 'measure-points',
          type: 'circle',
          source: 'geojson',
          paint: {
            'circle-radius': 5,
            'circle-color': '#000',
          },
          filter: ['in', '$type', 'Point'],
        });
        map.addLayer({
          id: 'measure-lines',
          type: 'line',
          source: 'geojson',
          layout: {
            'line-cap': 'round',
            'line-join': 'round',
          },
          paint: {
            'line-color': '#000',
            'line-width': 2.5,
          },
          filter: ['in', '$type', 'LineString'],
        });

        map.on('click', (e) => {
          const features = map.queryRenderedFeatures(e.point, {
            layers: ['measure-points'],
          });

          // Remove the linestring from the group
          // So we can redraw it based on the points collection
          if (geojson.features.length > 1) geojson.features.pop();

          // Clear the Distance container to populate it with a new value
          distanceContainer.innerHTML = '';

          // If a feature was clicked, remove it from the map
          if (features.length) {
            const id = features[0].properties.id;
            geojson.features = geojson.features.filter((point) => {
              return point.properties.id !== id;
            });
          } else {
            const point = {
              type: 'Feature',
              geometry: {
                type: 'Point',
                coordinates: [e.lngLat.lng, e.lngLat.lat],
              },
              properties: {
                id: String(new Date().getTime()),
              },
            };

            geojson.features.push(point);
          }

          if (geojson.features.length > 1) {
            linestring.geometry.coordinates = geojson.features.map((point) => {
              return point.geometry.coordinates;
            });

            geojson.features.push(linestring);

            // Populate the distanceContainer with total distance
            const value = document.createElement('pre');
            value.textContent = `Total distance: ${turf
              .length(linestring)
              .toLocaleString()}km`;
            distanceContainer.appendChild(value);
          }

          map.getSource('geojson').setData(geojson);
        });
      });

      map.on('mousemove', (e) => {
        const features = map.queryRenderedFeatures(e.point, {
          layers: ['measure-points'],
        });
        // UI indicator for clicking/hovering a point on the map
        map.getCanvas().style.cursor = features.length ?
    'pointer' :
    'crosshair';
      });
    </script>
  </body>
</html>
Last updated June 26, 2025.