Skidding variable & snow chains for buses

Hi,

I wanted to add a kind of snow chain function for the buses, that when a trigger is activated would show chains on the tyres (A texture change or a new model) and the bus wouldn't skid on the snow anymore.

The problem is that I don't know how omsi calculates when a bus is skidding and when tyres make friction with the terrain. I imagined this could be a variable, bud I did't find anything similar in my buses installed.

I know that you can know that a bus is skidding when the variable "Velocity" is different from "Velocity_Ground", that is the real speed of the bus, indipenden from rotation of wheels. But I don't know how you can make the wheels not skidding.

I think this is something already used with ASR scripts and I ask if someone knows how to make this thing working.

Thanks in advance.

Have a nice day .