This paper describes a microscopic traffic simulation tool for assessing the performance of ITS traffic and vehicle control systems. The scope of simulation is very broad. The traffic network is simulated in microscopic scale with nanoscopic components being available as well. The vehicles can be simulated down to basic physical properties including throttle and brake settings, fuel consumption and others. This allows for in-depth behavioural analysis of both individual vehicles and the whole traffic flow as a result of use of different traffic management systems. The simulator also allows investigating inter-vehicle interactions including platooning behaviour and its consequences such as the string stability problem. The simulator has been designed to be modular and easily extensible to allow for new functionality in future.