**1. Vehicle model for lateral stability**

According to Rempel [1] and Melo [2], the last unit (semi-trailer) of an *LCV* is the critical unit, since it is subjected to a high lateral acceleration compared to the tractor unit, which impacts the rollover threshold of the unit and the vehicle. Taking into account this aspect, a simplified trailer model (**Figure 1**) is modelled and analysed to calculate the *SRT* factor for *LVCs*.

The tyres, suspension, fifth wheel, and chassis are directly responsible for the *CG* movements; these movements are dependent on the forces acting on the trailer *CG*, such as weight (*W*), disturbance forces imposed by the ground, and lateral inertial force (*may*) when the vehicle makes a turn. During cornering or evasive manoeuvres, the weight and the lateral inertial force acting on the vehicle centre of gravity cause its displacement, which can lead to vehicle rollover.
