PTV Logistics Product Forum

Posted: **Wed Jan 07, 2026 12:09 pm**

The following usecase is quite generic within tour optimization and therefore I would like to describe how to model this:

We have a fleet with multiple vehicles we can utilize.
For some of the vehicles we can consider an optional trailer which means:
- If a trailer is attached to the vehicle it's COSTS and CAPACITIES change.
- The optimization should check whether a trailer is meaningful or not for a certain vehicle.
Bonus: some orders may prohibit a trailer vehicle to serve them.

Now here's the proper modeling approach - based on a single vehicle named "TheVehicle4711" (If you get this for a single vehicle you can easily derive how to use this in multiple vehicles):

Define a so-called Resource "Resource-4711" which is free of costs and limited to maximumVehicles=1:

Code: Select all

{
  "id" :"TheVehicle4711",
  "minimumBufferDuration" : 0,
  "constraints" : {
     "maximumVehicles" : 1
  },
  "costs": null,
  "categories" : ["Cat-Res-4711"]
}

Create two alternative vehicle objects : one with the trailer based properties (higher capacity, higher costs)

Code: Select all

{
  "id" : "vehicle-4711-no-trailer",
  "requiredResourceCategories": [ "Cat-Res-4711" ],
  ...
}

Code: Select all

{
  "id" : "vehicle-4711-with-trailer",
  "requiredResourceCategories": [ "Cat-Res-4711" ],
  ...
  "categories": ["hasTrailer"]
}

For the bonus requirement: forbid "hasTrailer" vehicles to serve certain orders:

use constraints.combinations.orderVehicle:

Code: Select all

{
    "combinations": {
      "orderVehicle": [
         "type": "FORBIDDEN_COMBINATION",
         "orderCategory": "no-trailer",
         "vehicleCategory" : "hasTrailer"
      ]      
    }
}

Mark the critical orders as "no-trailer" category:

Code: Select all

{
   "id" ; "order-23",
   "properties": {
      "categories" : [ "no-trailer" ]
   }   
}

PTV Logistics Product Forum

How to model vehicle with TRAILER / without TRAILER?

How to model vehicle with TRAILER / without TRAILER?