Hello Ernesto,
Yes, there is a way to get the VRP solver to do what you want.
To take capacity into account, use the PickupQuantities field in your Orders (representing students or bus stops) and the Capacities field in your Routes (representing the buses/driver/path). For both of these fields, you should have two values in one cell: one for passengers without wheelchairs and one for passengers with wheelchairs. The values need to be separated by a space. For example, if the bus has 9 seats and 1 spots for a wheelchair, the values would be entered in one cell as:
9 1
If an order represents a person who rides a wheelchair, the value would be ented as:
0 1
The Capacity Count property on the Analysis Settings tab of the Layer Properties dialog should have a value of 2. This tells the solver you want to model two capacities, which in your case represents passengers without wheelchairs and passengers with wheelchairs.
To model driver salaries, use the CostPerUnitTime field in the Routes layer. You'll need to convert their wages into the units that you set for the Time Field Units property on the Analysis Settings tab of the Layer Properties dialog. If you have hours set, you can specify a value that represents wages in $/hour, if you have the property set to 'Minutes', you would need to set the CostPerUnitTime field values in $/Minute.
To model gas and maintenance costs, use the CostPerUnitDistance field in the Routes layer. It functions in the same way CostPerUnitTime works. The costs are set per unit distance. You specify the distance units for the analysis in the Distance Field Units property of the Layer Properties dialog.
I hope this is helpful. Let me know if I can clarify anything.
Robert