The working width is a yardstick for the deformation of the system upon impact.
It is usually considered the main parameter when calculating the required free area behind the system to make the system work properly.
The working width is calculated as the maximum distance from the front of the system before the collision to the maximum deformation of the main components of the system after collision with a heavier vehicle.
The working width is divided into 8 classes from W1 to W8 according to the increasing deformation of the system.