Create back-to-back trips

This document describes how to create a back-to-back trip, set the correct fields, and assign it to a vehicle to fulfill. It assumes you have set up Fleet Engine, you have created vehicles, have a working driver app, and optionally, a consumer app. You should also be familiar with the various trip scenarios available for on-demand trips. See the following related guides for that:

• Set up Fleet Engine
• Create a vehicle
• Trip scenarios in the On-demand tripsoverview

Trip creation basics

This section describes the request details necessary for creating a trip in Fleet Engine. You issue a creation request using either gRPC and REST.

• CreateTrip() method: gRPC or REST
• CreateTripRequest message: gRPC only

Trip Fields

Use the following fields to create a trip in Fleet Engine. You can use different fields for the different kinds of trips: single- or multi-destination, back-to-back, or shared pooling trips. You can supply the optional fields when you create the trip, or you can set them later when you update the trip.

Example: create a back-to-back trip

The following demonstrates how to create a back-to-back trip and assign it to a vehicle. In this scenario, trip creation is the same as for a single-destination trip. It's only later that you create another trip and assign it to a vehicle with an already-active trip.

  // A vehicle with ID 'my-vehicle' is already created and it is assigned to a trip with ID 'current-trip'. 
 static 
  
 final 
  
 String 
  
 PROJECT_ID 
  
 = 
  
 "my-rideshare-co-gcp-project" 
 ; 
 static 
  
 final 
  
 String 
  
 VEHICLE_ID 
  
 = 
 " my-vehicle" 
 ; 
 static 
  
 final 
  
 String 
  
 TRIP_ID 
  
 = 
  
 "back-to-back-trip" 
 ); 
 TripServiceBlockingStub 
  
 tripService 
  
 = 
  
 TripService 
 . 
 newBlockingStub 
 ( 
 channel 
 ); 
 String 
  
 parent 
  
 = 
  
 "providers/" 
  
 + 
  
 PROJECT_ID 
 ; 
 Trip 
  
 trip 
  
 = 
  
 Trip 
 . 
 newBuilder 
 () 
  
 . 
 setTripType 
 ( 
 TripType 
 . 
 EXCLUSIVE 
 ) 
  
 . 
 setPickupPoint 
 ( 
  
 TerminalLocation 
 . 
 newBuilder 
 (). 
 setPoint 
 ( 
  
 LatLng 
 . 
 newBuilder 
 () 
  
 . 
 setLatitude 
 ( 
 - 
 6.195139 
 ). 
 setLongitude 
 ( 
 106.820826 
 ))) 
  
 . 
 setDropoffPoint 
 ( 
  
 TerminalLocation 
 . 
 newBuilder 
 (). 
 setPoint 
 ( 
  
 LatLng 
 . 
 newBuilder 
 () 
  
 . 
 setLatitude 
 ( 
 - 
 6.1275 
 ). 
 setLongitude 
 ( 
 106.6537 
 ))) 
  
 . 
 setVehicleId 
 ( 
 VEHICLE_ID 
 ) 
  
 . 
 build 
 (); 
 // Create trip request 
 CreateTripRequest 
  
 createTripRequest 
  
 = 
  
 CreateTripRequest 
 . 
 newBuilder 
 () 
  
 . 
 setParent 
 ( 
 parent 
 ) 
  
 . 
 setTripId 
 ( 
 TRIP_ID 
 ) 
  
 . 
 setTrip 
 ( 
 trip 
 ) 
  
 . 
 build 
 (); 
 // Error handling. 
 try 
  
 { 
  
 // Fleet Engine automatically assigns a 'waypoints' list to the trip containing 
  
 // the vehicle's current trip waypoints. 
  
 Trip 
  
 createdTrip 
  
 = 
  
 tripService 
 . 
 createTrip 
 ( 
 createTripRequest 
 ); 
 } 
  
 catch 
  
 ( 
 StatusRuntimeException 
  
 e 
 ) 
  
 { 
  
 Status 
  
 s 
  
 = 
  
 e 
 . 
 getStatus 
 (); 
  
 switch 
  
 ( 
 s 
 . 
 getCode 
 ()) 
  
 { 
  
 case 
  
 ALREADY_EXISTS 
 : 
  
 break 
 ; 
  
 case 
  
 PERMISSION_DENIED 
 : 
  
 break 
 ; 
  
 } 
  
 return 
 ; 
 } 
 

Update back-to-back trips

When you assign a vehicle for a back-to-back trip, you assign a trip to a vehicle even if it has already been assigned one.

Any trip created in Fleet Engine must be assigned to a vehicle in order for Fleet Engine to calculate trip ETAs and track it. You can do this either during trip creation or later when you update the trip.

After you assign the trip to a vehicle, Fleet Engine automatically adds the waypoints associated with the back-to-back trips to the vehicle's waypoints field. A trip's remainingWaypoints field contains a list of all of the waypoints, including those from other trips that will be visited before the trip's drop-off.

For example, consider two back-to-back trips: Trip A and Trip B . The vehicle has picked up the consumer for Trip A , and while en route to the drop-off location, the driver receives a request to pickup another consumer for the next trip, Trip B .

• Calling getVehicle() returns remainingWaypoints that contain:
  A _Drop-off → B _Pickup → B _Drop-off .
• Either getTrip() or the onTripRemainingWaypointsUpdated callback for Trip A returns remainingWaypoints that contain:
  A _Drop-off .
• Either getTrip() or the onTripRemainingWaypointsUpdated callback for Trip B returns remainingWaypoints that contain:
  A _Drop-off → B _Pickup → and B _Drop-off .

What's next

• Create shared pooling trips
• Set up the Driver SDK