Optimize the order of stops on your route

By default, the Routes API Compute Routes method calculates a route through multiple stops, called stopover waypoints, in the order that you provide them.

You can have the Routes API optimize the provided route by rearranging stops in a more efficient order. Waypoint optimization optimizes for travel time but also considers other factors such as distance and number of turns when deciding which route is the most efficient.

To optimize waypoints

  1. Make sure none of the waypoints in the route have via set to true, for example: {"address": "Clare,SA", "via": true}. For more information about intermediate waypoints, see Specify intermediate waypoints.

  2. Make sure the routing_preference is not set to TRAFFIC_AWARE_OPTIMAL.

  3. Set optimize_waypoint_order to true. For example:

    "optimizeWaypointOrder": "true",

  4. Specify the routes.optimizedIntermediateWaypointIndex field in the field mask:

    REST

    -H X-Goog-FieldMask: routes.optimizedIntermediateWaypointIndex

    RPC

    const (fieldMask = "routes.optimizedIntermediateWaypointIndex")

Understand how waypoint order is optimized

Here's how the Routes API optimizes the order of waypoints in a route:

  1. Automatically indexes the waypoints based on the order you provide them in the request, starting with 0.

  2. Optimizes the order of the waypoints using the index numbers it assigned to the waypoints in the request.

  3. Returns the optimized waypoint order in the routes object, in the waypoint_order field, under routes.optimizedIntermediateWaypointIndex.

Example

This request asks for optimization for a route from Adelaide, South Australia, to each of South Australia's main wine regions, and then returning to Adelaide.

curl -X POST -H 'content-type: application/json' -d ' {
  "origin": {
    "address": "Adelaide,SA"
  },
  "destination": {
    "address": "Adelaide,SA"
  },
  "intermediates": [
    {"address": "Barossa+Valley,SA"},
    {"address": "Clare,SA"},
    {"address": "Coonawarra,SA"},
    {"address": "McLaren+Vale,SA"}
  ],
  "travelMode": "DRIVE",
  "optimizeWaypointOrder": "true"
  }' \
-H 'Content-Type: application/json' \
-H 'X-Goog-Api-Key: YOUR_API_KEY' \
-H 'X-Goog-FieldMask: routes,geocodingResults.intermediates.intermediateWaypointRequestIndex' \
'https://routes.googleapis.com/directions/v2:computeRoutes'

The Routes API indexes the intermediate waypoints provided in the request, starting at 0. For example:

0    {"address": "Barossa+Valley,SA"},
1    {"address": "Clare,SA"},
2    {"address": "Coonawarrav,SA"},
3    {"address": "McLaren+Vale,SA"}

Using the index numbers for the four waypoints provided in the request, the service then returns the optimized order:

"optimizedIntermediateWaypointIndex": [
                3,
                2,
                0,
                1
            ]