The introduction of safety belts in the passengers’ seats of coaches could have important repercussions increasing their safety under frontal impact and rollover. This type of vehicles has a particularity from cars or trucks: the safety belts are fixed directly to the seats and not to the vehicle structures. A lot of work has been made in Europe (and it is being made) to define requirements for seats, seats’ anchorages, restraint systems and safety belts’ anchorages to guarantee the correct retention of the passengers in their seats under frontal impacts. In case of rollover, the belted passengers increase the energy that must be absorbed by the superstructure because some of their mass must be considered us rigidly joined to the vehicle. This situation has been taking into account in the current European legislation (Regulation UN-ECE 66, Revision 01). This version of the Regulation has increased the requirements for the superstructure to assure that the behaviour of the superstructure is as good as in the vehicles without belted passengers preserving the survival space. This new revision is going to be mandatory for new types from October 2010 (and for new matriculations from October 2017), but a considerable number of coaches’ manufactures are modifying their structures under this new revision because they take in mind that if the safety belts are yet included in the coaches, the superstructure must be in accordance. This is an important effort of redesign: more resistant structures but without weight increase.