The purpose of using longer and sometimes heavier vehicle combinations, based on the European Modular System, is to reduce the environmental impact and to improve the transport economy. One of these combinations is the DUO2-combination, which consists of a tractor and two semitrailers. The trailers are connected with a converter dolly. The combination type has number VCMC 10 in NVF-report no 1/2007. The presented results are from tests regarding dynamic stability, acceleration, braking and swept path width, which are all concerned with safety. The results will be used in the ongoing project, “Performance Based Standards - Applicability and possible adjustments for the Swedish conditions”.