- [JSON representation](https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#SCHEMA_REPRESENTATION)
- [Visit](https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#Visit)
  - [JSON representation](https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#Visit.SCHEMA_REPRESENTATION)
- [VisitType](https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#VisitType)
- [Transition](https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#Transition)
  - [JSON representation](https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#Transition.SCHEMA_REPRESENTATION)
- [EncodedPolyline](https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#EncodedPolyline)
  - [JSON representation](https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#EncodedPolyline.SCHEMA_REPRESENTATION)
- [Break](https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#Break)
  - [JSON representation](https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#Break.SCHEMA_REPRESENTATION)
- [VehicleFullness](https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#VehicleFullness)
  - [JSON representation](https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#VehicleFullness.SCHEMA_REPRESENTATION)

A vehicle's route can be decomposed, along the time axis, like this (we assume there are n visits):

      |            |            |          |       |  T[2], |        |      |
      | Transition |  Visit #0  |          |       |  V[2], |        |      |
      |     #0     |    aka     |   T[1]   |  V[1] |  ...   | V[n-1] | T[n] |
      |  aka T[0]  |    V[0]    |          |       | V[n-2],|        |      |
      |            |            |          |       | T[n-1] |        |      |
      ^            ^            ^          ^       ^        ^        ^      ^
    vehicle    V[0].start   V[0].end     V[1].   V[1].    V[n].    V[n]. vehicle
     start     (arrival)   (departure)   start   end      start    end     end

Note that we make a difference between:

- "punctual events", such as the vehicle start and end and each visit's start and end (aka arrival and departure). They happen at a given second.
- "time intervals", such as the visits themselves, and the transition between visits. Though time intervals can sometimes have zero duration, i.e. start and end at the same second, they often have a positive duration.

Invariants:

- If there are n visits, there are n+1 transitions.
- A visit is always surrounded by a transition before it (same index) and a transition after it (index + 1).
- The vehicle start is always followed by transition #0.
- The vehicle end is always preceded by transition #n.

Zooming in, here is what happens during a `Transition` and a `Visit`:

    ---+---+---+-->
       |           TRANSITION[i]             |           VISIT[i]          |
       |                                     |                             |
       |  * TRAVEL: the vehicle moves from   |      PERFORM the visit:     |
       |    VISIT[i-1].departure_location to |                             |
       |    VISIT[i].arrival_location, which |  * Spend some time:         |
       |    takes a given travel duration    |    the "visit duration".    |
       |    and distance                     |                             |
       |                                     |  * Load or unload           |
       |  * BREAKS: the driver may have      |    some quantities from the |
       |    breaks (e.g. lunch break).       |    vehicle: the "demand".   |
       |                                     |                             |
       |  * WAIT: the driver/vehicle does    |                             |
       |    nothing. This can happen for     |                             |
       |    many reasons, for example when   |                             |
       |    the vehicle reaches the next     |                             |
       |    event's destination before the   |                             |
       |    start of its time window         |                             |
       |                                     |                             |
       |  * DELAY: *right before* the next   |                             |
       |    arrival. E.g. the vehicle and/or |                             |
       |    driver spends time unloading.    |                             |
       |                                     |                             |
    ---+---+---+-->
       ^                                     ^                             ^
    V[i-1].end                           V[i].start                    V[i].end

Lastly, here is how the TRAVEL, BREAKS, DELAY and WAIT can be arranged during a transition.

- They don't overlap.
- The DELAY is unique and *must* be a contiguous period of time right before the next visit (or vehicle end). Thus, it suffice to know the delay duration to know its start and end time.
- The BREAKS are contiguous, non-overlapping periods of time. The response specifies the start time and duration of each break.
- TRAVEL and WAIT are "preemptable": they can be interrupted several times during this transition. Clients can assume that travel happens "as soon as possible" and that "wait" fills the remaining time.

A (complex) example:

                                   TRANSITION[i]
    --++---+---++-->
      ||     |       |           |       |           |         |         ||
      ||  T  |   B   |     T     |       |     B     |         |    D    ||
      ||  r  |   r   |     r     |   W   |     r     |    W    |    e    ||
      ||  a  |   e   |     a     |   a   |     e     |    a    |    l    ||
      ||  v  |   a   |     v     |   i   |     a     |    i    |    a    ||
      ||  e  |   k   |     e     |   t   |     k     |    t    |    y    ||
      ||  l  |       |     l     |       |           |         |         ||
      ||     |       |           |       |           |         |         ||
    --++---++-->

| JSON representation |
|---|
| ``` { "vehicleIndex": integer, "vehicleLabel": string, "vehicleStartTime": string, "vehicleEndTime": string, "visits": [ { object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#Visit`) } ], "transitions": [ { object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#Transition`) } ], "hasTrafficInfeasibilities": boolean, "routePolyline": { object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#EncodedPolyline`) }, "breaks": [ { object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#Break`) } ], "metrics": { object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/AggregatedMetrics`) }, "vehicleFullness": { object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#VehicleFullness`) }, "routeCosts": { string: number, ... }, "routeTotalCost": number } ``` |

| Fields ||
|---|---|
| `vehicleIndex` | `integer` Vehicle performing the route, identified by its index in the source `ShipmentModel`. |
| `vehicleLabel` | `string` Label of the vehicle performing this route, equal to `ShipmentModel.vehicles(vehicleIndex).label`, if specified. |
| `vehicleStartTime` | ``string (`https://protobuf.dev/reference/protobuf/google.protobuf#timestamp` format)`` Time at which the vehicle starts its route. Uses RFC 3339, where generated output will always be Z-normalized and use 0, 3, 6 or 9 fractional digits. Offsets other than "Z" are also accepted. Examples: `"2014-10-02T15:01:23Z"`, `"2014-10-02T15:01:23.045123456Z"` or `"2014-10-02T15:01:23+05:30"`. |
| `vehicleEndTime` | ``string (`https://protobuf.dev/reference/protobuf/google.protobuf#timestamp` format)`` Time at which the vehicle finishes its route. Uses RFC 3339, where generated output will always be Z-normalized and use 0, 3, 6 or 9 fractional digits. Offsets other than "Z" are also accepted. Examples: `"2014-10-02T15:01:23Z"`, `"2014-10-02T15:01:23.045123456Z"` or `"2014-10-02T15:01:23+05:30"`. |
| `visits[]` | ``object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#Visit`)`` Ordered sequence of visits representing a route. visits\[i\] is the i-th visit in the route. If this field is empty, the vehicle is considered as unused. |
| `transitions[]` | ``object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#Transition`)`` Ordered list of transitions for the route. |
| `hasTrafficInfeasibilities` | `boolean` When `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/projects.locations/optimizeTours#body.request_body.FIELDS.consider_road_traffic`, is set to true, this field indicates that inconsistencies in route timings are predicted using traffic-based travel duration estimates. There may be insufficient time to complete traffic-adjusted travel, delays, and breaks between visits, before the first visit, or after the last visit, while still satisfying the visit and vehicle time windows. For example, startTime(previous_visit) + duration(previous_visit) + travelDuration(previous_visit, next_visit) > startTime(next_visit) Arrival at next_visit will likely happen later than its current time window due the increased estimate of travel time `travelDuration(previous_visit, next_visit)` due to traffic. Also, a break may be forced to overlap with a visit due to an increase in travel time estimates and visit or break time window restrictions. |
| `routePolyline` | ``object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#EncodedPolyline`)`` The encoded polyline representation of the route. This field is only populated if `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/projects.locations/optimizeTours#body.request_body.FIELDS.populate_polylines` is set to true. |
| `breaks[]` | ``object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#Break`)`` Breaks scheduled for the vehicle performing this route. The `breaks` sequence represents time intervals, each starting at the corresponding `startTime` and lasting `duration` seconds. |
| `metrics` | ``object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/AggregatedMetrics`)`` Duration, distance and load metrics for this route. The fields of `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/AggregatedMetrics` are summed over all `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#FIELDS.transitions` or `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#FIELDS.visits`, depending on the context. |
| `vehicleFullness` | ``object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#VehicleFullness`)`` `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#VehicleFullness` field for computing how close the capped metrics are to their respective vehicle limits. Its fields are ratios between a capped metric field (e.g. `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/AggregatedMetrics#FIELDS.travel_distance_meters`) and the related vehicle limit (e.g. `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#Vehicle.FIELDS.route_distance_limit`). Experimental: This field's behavior or existence may change in future. |
| `routeCosts` | `map (key: string, value: number)` Cost of the route, broken down by cost-related request fields. The keys are proto paths, relative to the input OptimizeToursRequest, e.g. "model.shipments.pickups.cost", and the values are the total cost generated by the corresponding cost field, aggregated over the whole route. In other words, costs\["model.shipments.pickups.cost"\] is the sum of all pickup costs over the route. All costs defined in the model are reported in detail here with the exception of costs related to TransitionAttributes that are only reported in an aggregated way as of 2022/01. |
| `routeTotalCost` | `number` Total cost of the route. The sum of all costs in the cost map. |

## Visit

A visit performed during a route. This visit corresponds to a pickup or a delivery of a `Shipment`.

| JSON representation |
|---|
| ``` { "shipmentIndex": integer, "isPickup": boolean, "visitRequestIndex": integer, "startTime": string, "loadDemands": { string: { object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/Load`) }, ... }, "detour": string, "shipmentLabel": string, "visitLabel": string, "visitType": enum (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#VisitType`), "injectedSolutionLocationToken": integer } ``` |

| Fields ||
|---|---|
| `shipmentIndex` | `integer` Index of the `shipments` field in the source `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel`. |
| `isPickup` | `boolean` If true the visit corresponds to a pickup of a `Shipment`. Otherwise, it corresponds to a delivery. |
| `visitRequestIndex` | `integer` Index of `VisitRequest` in either the pickup or delivery field of the `Shipment` (see `isPickup`). |
| `startTime` | ``string (`https://protobuf.dev/reference/protobuf/google.protobuf#timestamp` format)`` Time at which the visit starts. Note that the vehicle may arrive earlier than this at the visit location. Times are consistent with the `ShipmentModel`. Uses RFC 3339, where generated output will always be Z-normalized and use 0, 3, 6 or 9 fractional digits. Offsets other than "Z" are also accepted. Examples: `"2014-10-02T15:01:23Z"`, `"2014-10-02T15:01:23.045123456Z"` or `"2014-10-02T15:01:23+05:30"`. |
| `loadDemands` | ``map (key: string, value: object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/Load`))`` Total visit load demand as the sum of the shipment and the visit request `loadDemands`. The values are negative if the visit is a delivery. Demands are reported for the same types as the `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#Transition` (see this field). |
| `detour` | ``string (`https://protobuf.dev/reference/protobuf/google.protobuf#duration` format)`` Extra detour time due to the shipments visited on the route before the visit and to the potential waiting time induced by time windows. If the visit is a delivery, the detour is computed from the corresponding pickup visit and is equal to: startTime(delivery) - startTime(pickup) - (duration(pickup) + travel duration from the pickup location to the delivery location). Otherwise, it is computed from the vehicle `startLocation` and is equal to: startTime - vehicleStartTime - travel duration from the vehicle's `startLocation` to the visit. |
| `shipmentLabel` | `string` Copy of the corresponding `Shipment.label`, if specified in the `Shipment`. |
| `visitLabel` | `string` Copy of the corresponding `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#VisitRequest.FIELDS.label`, if specified in the `VisitRequest`. |
| `visitType` | ``enum (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#VisitType`)`` Optional. Specifies the type of the visit. Overrides the `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#Visit.FIELDS.is_pickup` field. |
| `injectedSolutionLocationToken` | `integer` An opaque token representing information about a visit location. This field may be populated in the result routes' visits when `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#VisitRequest.FIELDS.avoid_u_turns` was set to true for this visit or if `ShipmentModel.avoid_u_turns` was set to true in the request `OptimizeToursRequest`. Experimental: See <https://developers.google.com/maps/tt/route-optimization/experimental/u-turn-avoidance/make-request> for more details. |

## VisitType

Indicates whether the visit is a pickup, a delivery, or a visit to a `Stop`. Visits to a stop are used only when multimodal optimization is enabled.

| Enums ||
|---|---|
| `VISIT_TYPE_UNSPECIFIED` | Unspecified visit type. |
| `PICKUP_SHIPMENT` | Visit corresponds to a shipment pickup. |
| `DELIVER_SHIPMENT` | Visit corresponds to a shipment delivery. |

## Transition

Transition between two events on the route. See the description of `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute`.

If the vehicle does not have a `startLocation` and/or `endLocation`, the corresponding travel metrics are 0.

| JSON representation |
|---|
| ``` { "travelDuration": string, "travelDistanceMeters": number, "trafficInfoUnavailable": boolean, "delayDuration": string, "breakDuration": string, "waitDuration": string, "totalDuration": string, "startTime": string, "routePolyline": { object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#EncodedPolyline`) }, "routeToken": string, "vehicleLoads": { string: { object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/VehicleLoad`) }, ... } } ``` |

| Fields ||
|---|---|
| `travelDuration` | ``string (`https://protobuf.dev/reference/protobuf/google.protobuf#duration` format)`` Travel duration during this transition. |
| `travelDistanceMeters` | `number` Distance traveled during the transition. |
| `trafficInfoUnavailable` | `boolean` When traffic is requested via `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/projects.locations/optimizeTours#body.request_body.FIELDS.consider_road_traffic`, and the traffic info couldn't be retrieved for a `Transition`, this boolean is set to true. This may be temporary (rare hiccup in the realtime traffic servers) or permanent (no data for this location). |
| `delayDuration` | ``string (`https://protobuf.dev/reference/protobuf/google.protobuf#duration` format)`` Sum of the delay durations applied to this transition. If any, the delay starts exactly `delayDuration` seconds before the next event (visit or vehicle end). See `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#TransitionAttributes.FIELDS.delay`. |
| `breakDuration` | ``string (`https://protobuf.dev/reference/protobuf/google.protobuf#duration` format)`` Sum of the duration of the breaks occurring during this transition, if any. Details about each break's start time and duration are stored in `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#FIELDS.breaks`. |
| `waitDuration` | ``string (`https://protobuf.dev/reference/protobuf/google.protobuf#duration` format)`` Time spent waiting during this transition. Wait duration corresponds to idle time and does not include break time. Also note that this wait time may be split into several non-contiguous intervals. |
| `totalDuration` | ``string (`https://protobuf.dev/reference/protobuf/google.protobuf#duration` format)`` Total duration of the transition, provided for convenience. It is equal to: - next visit `startTime` (or `vehicleEndTime` if this is the last transition) - this transition's `startTime`; - if `ShipmentRoute.has_traffic_infeasibilities` is false, the following additionally holds: \`totalDuration = travelDuration + delayDuration - breakDuration + waitDuration\`. |
| `startTime` | ``string (`https://protobuf.dev/reference/protobuf/google.protobuf#timestamp` format)`` Start time of this transition. Uses RFC 3339, where generated output will always be Z-normalized and use 0, 3, 6 or 9 fractional digits. Offsets other than "Z" are also accepted. Examples: `"2014-10-02T15:01:23Z"`, `"2014-10-02T15:01:23.045123456Z"` or `"2014-10-02T15:01:23+05:30"`. |
| `routePolyline` | ``object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#EncodedPolyline`)`` The encoded polyline representation of the route followed during the transition. This field is only populated if `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/projects.locations/optimizeTours#body.request_body.FIELDS.populate_transition_polylines` is set to true. |
| `routeToken` | `string` Output only. An opaque token that can be passed to [Navigation SDK](https://developers.google.com/maps/documentation/navigation) to reconstruct the route during navigation, and, in the event of rerouting, honor the original intention when the route was created. Treat this token as an opaque blob. Don't compare its value across requests as its value may change even if the service returns the exact same route. This field is only populated if `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/projects.locations/optimizeTours#body.request_body.FIELDS.populate_transition_polylines` is set to true. |
| `vehicleLoads` | ``map (key: string, value: object (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/VehicleLoad`))`` Vehicle loads during this transition, for each type that either appears in this vehicle's `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#Vehicle.FIELDS.load_limits`, or that have non-zero `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#Shipment.FIELDS.load_demands` on some shipment performed on this route. The loads during the first transition are the starting loads of the vehicle route. Then, after each visit, the visit's `loadDemands` are either added or subtracted to get the next transition's loads, depending on whether the visit was a pickup or a delivery. |

## EncodedPolyline

The encoded representation of a polyline. More information on polyline encoding can be found here: <https://developers.google.com/maps/documentation/utilities/polylinealgorithm> <https://developers.google.com/maps/documentation/javascript/reference/geometry#encoding>.

| JSON representation |
|---|
| ``` { "points": string } ``` |

| Fields ||
|---|---|
| `points` | `string` String representing encoded points of the polyline. |

## Break

Data representing the execution of a break.

| JSON representation |
|---|
| ``` { "startTime": string, "duration": string } ``` |

| Fields ||
|---|---|
| `startTime` | ``string (`https://protobuf.dev/reference/protobuf/google.protobuf#timestamp` format)`` Start time of a break. Uses RFC 3339, where generated output will always be Z-normalized and use 0, 3, 6 or 9 fractional digits. Offsets other than "Z" are also accepted. Examples: `"2014-10-02T15:01:23Z"`, `"2014-10-02T15:01:23.045123456Z"` or `"2014-10-02T15:01:23+05:30"`. |
| `duration` | ``string (`https://protobuf.dev/reference/protobuf/google.protobuf#duration` format)`` Duration of a break. |

## VehicleFullness

`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#VehicleFullness` is a metric which computes how full a vehicle is. Each `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentRoute#VehicleFullness` field is between 0 and 1, computed as the ratio between a capped metric field (e.g. `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/AggregatedMetrics#FIELDS.travel_distance_meters`) and its related vehicle limit (e.g. `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#Vehicle.FIELDS.route_distance_limit`), if it exists. Otherwise the fullness ratio stays unset. If the limit is 0, the field is set to 1. Note: when a route is subject to traffic infeasibilities, some raw fullness ratios might exceed 1.0, e.g. the vehicle might exceed its distance limit. In these cases, we cap the fullness values at 1.0.

| JSON representation |
|---|
| ``` { "maxFullness": number, "distance": number, "travelDuration": number, "activeDuration": number, "maxLoad": number, "activeSpan": number } ``` |

| Fields ||
|---|---|
| `maxFullness` | `number` Maximum of all other fields in this message. |
| `distance` | `number` The ratio between `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/AggregatedMetrics#FIELDS.travel_distance_meters` and `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#Vehicle.FIELDS.route_distance_limit`. If `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#Vehicle.FIELDS.route_distance_limit` is unset, this field will be unset. |
| `travelDuration` | `number` The ratio between \[AggregatedMetrics.travel_duration_seconds\]\[\] and `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#Vehicle.FIELDS.travel_duration_limit`. If `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#Vehicle.FIELDS.travel_duration_limit` is unset, this field will be unset. |
| `activeDuration` | `number` The ratio between \[AggregatedMetrics.total_duration_seconds\]\[\] and `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#Vehicle.FIELDS.route_duration_limit`. If `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#Vehicle.FIELDS.route_duration_limit` is unset, this field will be unset. |
| `maxLoad` | `number` The maximum ratio among all types of \[AggregatedMetrics.max_load\]\[\] and their respective `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#Vehicle.FIELDS.load_limits`. If all `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#Vehicle.FIELDS.load_limits` fields are unset, this field will be unset. |
| `activeSpan` | `number` The ratio (vehicleEndTime - vehicleStartTime) / (latestVehicleEndTime - earliestVehicleStartTime) for a given vehicle. If the denominator is not present, it uses (`https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#FIELDS.global_end_time` - `https://developers.google.com/maps/documentation/route-optimization/reference/rest/v1/ShipmentModel#FIELDS.global_start_time`) instead. |