By default, the Routes librarycomputeRoutes 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 havevia set totrue.
2. Make sure theroutingPreference is not set toTRAFFIC_AWARE_OPTIMAL.
3. SetoptimizeWaypointOrder totrue.
4. Specify theoptimizedIntermediateWaypointIndices field in the field mask.

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 order of the waypoints in the response underoptimizedIntermediateWaypointIndices.

Example request

The following example shows how to request optimized waypoints in a route from Adelaide, South Australia, to each of South Australia's main wine regions, and then returning to Adelaide.

constrequest={origin:'Adelaide, SA',destination:'Adelaide, SA',intermediates:[{location:"Barossa+Valley,SA"},{location:"Clare,SA"},{location:"Coonawarra,SA"},{location:"McLaren+Vale,SA"},],travelMode:'DRIVING',optimizeWaypointOrder:true,fields:['path','optimizedIntermediateWaypointIndices'],};

Example response

Response:[{"optimizedIntermediateWaypointIndices":[3,// McLaren+Vale, SA2,// Coonawarra, SA0,// Barossa+Valley, SA1// Clare, SA],...