In the years past, quite a number of relevant test procedures including appropriate criteria of description and evaluation respectively have been developed to objectively describe and assess handling and braking characteristics of passenger cars and passenger car-trailer combinations. These test procedures are basically applicable to commercial vehicles and combinations as well provided that either the starting conditions or the criteria of description are adapted to the special features of this particular class of vehicles. With regard to the various design principles of commercial vehicles and the ever increasing advances of vehicle combinations ensuring optimum utilisation of cargo space, i.e. single trucks or buses, truck-trailer combinations, semi-trailer combinations, articulated buses and short coupling truck combinations, the handling characteristics of these vehicles are definitely more distinct from each other. The application of suitable test procedures on the one hand gives the feasibility to classify new vehicle combinations in comparison with existing designs and on the other side to optimize handling and braking characteristics in respect of increased traffic safety. Within this paper test and measuring procedures generally applied to evaluate handling and braking characteristics of heavy commercial vehicles will be described. By measurements taken by the authors for a double-decker and a high-decker coach, a 16-t truck, two 7,5-t trucks and a special type 38-t semi-trailer combination, significant measuring variables are pointed out which can be used for evaluating the handling characteristics of the specific vehicle type.
Samenvatting