Google map direction services waypoints more than 50

Question

Documentation says that waypoints limit is 8 points. But I have to find best waypoints order list from more than 50 waypoints. How to do that?

I am able to find waypoints order by using Start + Destination + 8 Waypoints But I need help for more than 50 Waypoints

Answer 1

function initMap() {
    var service = new google.maps.DirectionsService;
    var map = new google.maps.Map(document.getElementById('map'));

    // list of points
    var stations = [
        {lat: 48.9812840, lng: 21.2171920, name: 'Station 1'},
        {lat: 48.9832841, lng: 21.2176398, name: 'Station 2'},
        {lat: 48.9856443, lng: 21.2209088, name: 'Station 3'},
        {lat: 48.9861461, lng: 21.2261563, name: 'Station 4'},
        {lat: 48.9874682, lng: 21.2294855, name: 'Station 5'},
        {lat: 48.9909244, lng: 21.2295512, name: 'Station 6'},
        {lat: 48.9928871, lng: 21.2292352, name: 'Station 7'},
        {lat: 48.9921334, lng: 21.2246742, name: 'Station 8'},
        {lat: 48.9943196, lng: 21.2234792, name: 'Station 9'},
        {lat: 48.9966345, lng: 21.2221262, name: 'Station 10'},
        {lat: 48.9981191, lng: 21.2271386, name: 'Station 11'},
        {lat: 49.0009168, lng: 21.2359527, name: 'Station 12'},
        {lat: 49.0017950, lng: 21.2392890, name: 'Station 13'},
        {lat: 48.9991912, lng: 21.2398272, name: 'Station 14'},
        {lat: 48.9959850, lng: 21.2418410, name: 'Station 15'},
        {lat: 48.9931772, lng: 21.2453901, name: 'Station 16'},
        {lat: 48.9963512, lng: 21.2525850, name: 'Station 17'},
        {lat: 48.9985134, lng: 21.2508423, name: 'Station 18'},
        {lat: 49.0085000, lng: 21.2508000, name: 'Station 19'},
        {lat: 49.0093000, lng: 21.2528000, name: 'Station 20'},
        {lat: 49.0103000, lng: 21.2560000, name: 'Station 21'},
        {lat: 49.0112000, lng: 21.2590000, name: 'Station 22'},
        {lat: 49.0124000, lng: 21.2620000, name: 'Station 23'},
        {lat: 49.0135000, lng: 21.2650000, name: 'Station 24'},
        {lat: 49.0149000, lng: 21.2680000, name: 'Station 25'},
        {lat: 49.0171000, lng: 21.2710000, name: 'Station 26'},
        {lat: 49.0198000, lng: 21.2740000, name: 'Station 27'},
        {lat: 49.0305000, lng: 21.3000000, name: 'Station 28'},
    ];
    
    // Zoom and center map automatically by stations (each station will be in visible map area)
    var lngs = stations.map(function(station) { return station.lng; });
    var lats = stations.map(function(station) { return station.lat; });
    map.fitBounds({
        west: Math.min.apply(null, lngs),
        east: Math.max.apply(null, lngs),
        north: Math.min.apply(null, lats),
        south: Math.max.apply(null, lats),
    });
    
    // Show stations on the map as markers
    for (var i = 0; i < stations.length; i++) {
        if (!stations[i].name)
            continue;
        new google.maps.Marker({
            position: stations[i],
            map: map,
            title: stations[i].name
        });
    }

    // Divide route to several parts because max stations limit is 25 (23 waypoints + 1 origin + 1 destination)
    for (var i = 0, parts = [], max = 8 - 1; i < stations.length; i = i + max)
        parts.push(stations.slice(i, i + max + 1));

    // Callback function to process service results
    var service_callback = function(response, status) {
        if (status != 'OK') {
            console.log('Directions request failed due to ' + status);
            return;
        }
        var renderer = new google.maps.DirectionsRenderer;
        renderer.setMap(map);
        renderer.setOptions({ suppressMarkers: true, preserveViewport: true });
        renderer.setDirections(response);
    };
        
    // Send requests to service to get route (for stations count <= 25 only one request will be sent)
    for (var i = 0; i < parts.length; i++) {
        // Waypoints does not include first station (origin) and last station (destination)
        var waypoints = [];
        for (var j = 1; j < parts[i].length - 1; j++)
            waypoints.push({location: parts[i][j], stopover: false});
        // Service options
        var service_options = {
            origin: parts[i][0],
            destination: parts[i][parts[i].length - 1],
            waypoints: waypoints,
            travelMode: 'WALKING'
        };
        // Send request
        service.route(service_options, service_callback);
    }
  }

html, body {
    height: 100%;
    margin: 0;
    padding: 0;
}
#map {
    height: 100%;     
    width: 100%;
    height: 100%;
}

<div id="map"></div>

<!-- without API KEY set variable "max" to 8 -->
<script async defer src="https://maps.googleapis.com/maps/api/js?callback=initMap"></script>

<!-- with API KEY set variable "max" to 25 -->
<!-- <script async defer src="https://maps.googleapis.com/maps/api/js?callback=initMap&key=YOUR_API_KEY"></script>-->

With following code you can use as many waypoints as you need and you will never get error MAX_WAYPOINTS_EXCEEDED. Do not forget to replace "YOUR_API_KEY" to your API KEY or remove &key=YOUR_API_KEY from google API URL and set variable "max" to 8 (max = 25 when using API KEY, max = 8 when not using API KEY).

<div id="map"></div>
<script>
  function initMap() {
    var service = new google.maps.DirectionsService;
    var map = new google.maps.Map(document.getElementById('map'));

    // list of points
    var stations = [
        {lat: 48.9812840, lng: 21.2171920, name: 'Station 1'},
        {lat: 48.9832841, lng: 21.2176398, name: 'Station 2'},
        {lat: 48.9856443, lng: 21.2209088, name: 'Station 3'},
        {lat: 48.9861461, lng: 21.2261563, name: 'Station 4'},
        {lat: 48.9874682, lng: 21.2294855, name: 'Station 5'},
        {lat: 48.9909244, lng: 21.2295512, name: 'Station 6'},
        {lat: 48.9928871, lng: 21.2292352, name: 'Station 7'},
        {lat: 48.9921334, lng: 21.2246742, name: 'Station 8'},
        {lat: 48.9943196, lng: 21.2234792, name: 'Station 9'},
        {lat: 48.9966345, lng: 21.2221262, name: 'Station 10'},
        {lat: 48.9981191, lng: 21.2271386, name: 'Station 11'},
        {lat: 49.0009168, lng: 21.2359527, name: 'Station 12'},
        {lat: 49.0017950, lng: 21.2392890, name: 'Station 13'},
        {lat: 48.9991912, lng: 21.2398272, name: 'Station 14'},
        {lat: 48.9959850, lng: 21.2418410, name: 'Station 15'},
        {lat: 48.9931772, lng: 21.2453901, name: 'Station 16'},
        {lat: 48.9963512, lng: 21.2525850, name: 'Station 17'},
        {lat: 48.9985134, lng: 21.2508423, name: 'Station 18'},
        {lat: 49.0085000, lng: 21.2508000, name: 'Station 19'},
        {lat: 49.0093000, lng: 21.2528000, name: 'Station 20'},
        {lat: 49.0103000, lng: 21.2560000, name: 'Station 21'},
        {lat: 49.0112000, lng: 21.2590000, name: 'Station 22'},
        {lat: 49.0124000, lng: 21.2620000, name: 'Station 23'},
        {lat: 49.0135000, lng: 21.2650000, name: 'Station 24'},
        {lat: 49.0149000, lng: 21.2680000, name: 'Station 25'},
        {lat: 49.0171000, lng: 21.2710000, name: 'Station 26'},
        {lat: 49.0198000, lng: 21.2740000, name: 'Station 27'},
        {lat: 49.0305000, lng: 21.3000000, name: 'Station 28'},
        // ... as many other stations as you need
    ];

    // Zoom and center map automatically by stations (each station will be in visible map area)
    var lngs = stations.map(function(station) { return station.lng; });
    var lats = stations.map(function(station) { return station.lat; });
    map.fitBounds({
        west: Math.min.apply(null, lngs),
        east: Math.max.apply(null, lngs),
        north: Math.min.apply(null, lats),
        south: Math.max.apply(null, lats),
    });

    // Show stations on the map as markers
    for (var i = 0; i < stations.length; i++) {
        new google.maps.Marker({
            position: stations[i],
            map: map,
            title: stations[i].name
        });
    }

    // Divide route to several parts because max stations limit is 25 (23 waypoints + 1 origin + 1 destination)
    for (var i = 0, parts = [], max = 25 - 1; i < stations.length; i = i + max)
        parts.push(stations.slice(i, i + max + 1));

    // Service callback to process service results
    var service_callback = function(response, status) {
        if (status != 'OK') {
            console.log('Directions request failed due to ' + status);
            return;
        }
        var renderer = new google.maps.DirectionsRenderer;
        renderer.setMap(map);
        renderer.setOptions({ suppressMarkers: true, preserveViewport: true });
        renderer.setDirections(response);
    };

    // Send requests to service to get route (for stations count <= 25 only one request will be sent)
    for (var i = 0; i < parts.length; i++) {
        // Waypoints does not include first station (origin) and last station (destination)
        var waypoints = [];
        for (var j = 1; j < parts[i].length - 1; j++)
            waypoints.push({location: parts[i][j], stopover: false});
        // Service options
        var service_options = {
            origin: parts[i][0],
            destination: parts[i][parts[i].length - 1],
            waypoints: waypoints,
            travelMode: 'WALKING'
        };
        // Send request
        service.route(service_options, service_callback);
    }
  }
</script>
<script async defer src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap"></script>

Answer 2

I've created a workaround but it is a bit more expensive (in terms of API calls) to use.

Instead of creating a single call with the start, end, and waypoints LatLngs, I split the waypoints into pairs make the calls per pair.

Example:

Problem: Route and get Directions for 100 points

Solution:

• Call 1: Point 1 and Point 2
• Call 2: Point 2 and Point 3

• Call 3: Point 3 and Point 4

  ... and so on.

With this solution you'll never have to worry about the 8 waypoint limitation since you're only making a 2 point query every time. The weakness of this solution is you will be creating a lot of calls and it will eat up your 2500 free calls per day if not used properly.