Computing a Route Examples

You can retrieve a set of routes from the Routes Preferred API by sending an HTTP POST request to the following resource:

https://routespreferred.googleapis.com/v1:computeRoutes

Include your request options, formatted in JSON, in the message body. For information about the complete set of options, see the computeRoutes Request Body.

Example request body

The following JSON code demonstrates how to construct a typical request body for a computeRoutes request.

POST /v1:computeRoutes
Host: routespreferred.googleapis.com
Content-Type: application/json
X-Goog-Api-Key: YOUR_API_KEY
X-Goog-FieldMask: routes.duration,routes.distanceMeters,routes.polyline.encodedPolyline

{
  "origin":{
    "location":{
      "latLng":{
        "latitude": 37.419734,
        "longitude": -122.0827784
      }
    }
  },
  "destination":{
    "location":{
      "latLng":{
        "latitude": 37.417670,
        "longitude": -122.079595
      }
    }
  },
  "travelMode": "DRIVE",
  "routingPreference": "TRAFFIC_AWARE",
  "polylineQuality": "OVERVIEW",
  "departureTime": "2019-10-15T15:01:23.045123456Z",
  "computeAlternativeRoutes": false,
  "routeModifiers": {
    "avoidTolls": false,
    "avoidHighways": false,
    "avoidFerries": false
  },
  "languageCode": "en-US",
  "units": "IMPERIAL"
}

Example response body

The following JSON code is an example of the response body returned from the above call to computeRoutes.

{
  "routes": [
    {
      "distanceMeters": 772,
      "duration": "165s",
      "polyline": {
        "encodedPolyline": "ipkcFfichVnP@j@BLoFVwM{E?"
      }
    }
  ]
}

Example gRPC Request

The following shows an example gRPC request.

Go

package main

import (
	"context"
	"fmt"
	"log"
	"time"

	routespreferred "developers.google.com/maps/go/routespreferred/v1"
	"google.golang.org/api/option"
	routespb "google.golang.org/genproto/googleapis/maps/routes/v1"
	"google.golang.org/genproto/googleapis/type/latlng"
	"google.golang.org/grpc/metadata"
)

const (
	// https://cloud.google.com/iam/docs/creating-managing-service-account-keys#creating_service_account_keys
	credentialsFile = "service-account.json"
	// Note that setting the field mask to * is OK for testing, but discouraged in
	// production.
	// For example, for ComputeRoutes, set the field mask to
	// "routes.distanceMeters,routes.duration,routes.polyline.encodedPolyline"
	// in order to get the route distances, durations, and encoded polylines.
	fieldMask = "*"
)

func main() {
	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
	defer cancel()

	// instantiate a client
	c, err := routespreferred.NewRoutesPreferredClient(ctx,
		option.WithCredentialsFile(credentialsFile))
	defer c.Close()

	if err != nil {
		log.Fatal(err)
	}

	// create the origin using a latitude and longitude
	origin := &routespb.Waypoint{
		LocationType: &routespb.Waypoint_Location{
			Location: &routespb.Location{
				LatLng: &latlng.LatLng{
					Latitude:  37.417670,
					Longitude: -122.0827784,
				},
			},
		},
	}

	// create the destination using a latitude and longitude
	destination := &routespb.Waypoint{
		LocationType: &routespb.Waypoint_Location{
			Location: &routespb.Location{
				LatLng: &latlng.LatLng{
					Latitude:  37.417670,
					Longitude: -122.079595,
				},
			},
		},
	}

	// create the request with additional options
	req := &routespb.ComputeRoutesRequest{
		Origin:                   origin,
		Destination:              destination,
		TravelMode:               routespb.RouteTravelMode_DRIVE,
		RoutingPreference:        routespb.RoutingPreference_TRAFFIC_AWARE,
		ComputeAlternativeRoutes: true,
		Units:                    routespb.Units_METRIC,
		LanguageCode:             "en-us",
		RouteModifiers: &routespb.RouteModifiers{
			AvoidTolls:    false,
			AvoidHighways: true,
			AvoidFerries:  true,
		},
		PolylineQuality: routespb.PolylineQuality_OVERVIEW,
	}

	// set the field mask
	ctx = metadata.AppendToOutgoingContext(ctx, "X-Goog-Fieldmask", fieldMask)

	// execute rpc
	resp, err := c.ComputeRoutes(ctx, req)

	if err != nil {
		// "rpc error: code = InvalidArgument desc = Request contains an invalid
		// argument" may indicate that your project lacks access to Routes Preferred
		log.Fatal(err)
	}

	fmt.Printf("Duration of route %d", resp.Routes[0].Duration.Seconds)
}

main.go

Calculating toll fees example

The following example uses the computeRoutes method to return toll information with an estimated price when a toll pass is used.

This feature is enabled with the routes.travelAdvisory.tollInfo field mask specified in the request. The toll pass is specified in the route_modifiers field. The toll price returned is based on the pricing used by the specified pass. If more than one pass is specified, the least expensive pricing is returned.

Request:

curl -X POST -d '{
  "origin":{
    "location":{
      "lat_lng":{
        "latitude":47.7020056,
        "longitude":-122.3479236
      }
    }
  },
  "destination":{
    "location":{
      "lat_lng":{
        "latitude":47.6192234,
        "longitude": -122.1676792
      }
    }
  },
  "travel_mode":"DRIVE",
  "route_modifiers":{
    "vehicle_info":{
      "emission_type": "GASOLINE"
    },
    "toll_passes": [
      "US_MA_EZPASSMA",
      "US_WA_GOOD_TO_GO"
    ]
  }
}' \
-H 'Content-Type: application/json' \
-H 'X-Goog-Api-Key: <YOUR_API_KEY>' \
-H 'X-Goog-FieldMask: routes.duration,routes.distanceMeters,routes.travelAdvisory.tollInfo,routes.legs.travelAdvisory.tollInfo' \
'https://routespreferred.googleapis.com/v1alpha:computeRoutes'

Response:

{
  "routes": [
    {
      "legs": [
        {
          "travelAdvisory": {
            "tollInfo": {
              "estimatedPrice": [
                {
                  "currencyCode": "USD",
                  "units": "3",
                  "nanos": 400000000
                }
              ]
            }
          }
        }
      ],
      "distanceMeters": 22496,
      "duration": "1400s",
      "travelAdvisory": {
        "tollInfo": {
          "estimatedPrice": [
            {
              "currencyCode": "USD",
              "units": "3",
              "nanos": 400000000
            }
          ]
        }
      }
    }
  ]
}