Cargo securement methods and vehicle braking performance

According to road safety standards, the cargo must be secured to the carrying vehicle in such a way that it does not shift or fall, setting performance measures addressing specific acceleration levels that the cargo restraint system must withstand. For a braking manoeuvre, the mandatory acceleration level is 0.8 g. On the other hand, improved stopping distances are being demanded, involving accelerations on the order of 0.52 g. In this paper, a dynamic model is proposed to assess the braking performance of a cargo vehicle, as a function of the cargo securement method and pavement roughness. Results suggest that transient accelerations greater than 0.8 g can be attained during the braking manoeuvre, as a result of the cargo-vehicle decoupling, provoking that the braking forces be exerted on a diminished mass. A value of 1.1 g is recommended as a new mandatory braking acceleration level that the cargo securement method should withstand.