Abstract: Recently, considerable research has been focused on applying ad hoc wireless networking technology to on-the-move vehicles. Future intelligent transportation system technologies based on vehicle-to-vehicle (V2V) and vehicle-to-roadside (V2I) communications are actively being studied. In fact, V2V is considered useful for localized emergency and respond cases, while V2I is viewed as the long-haul pipe for noncritical information push and pull. In this talk, we will discuss about vehicular mobility and its influence to performance of vehicular communication. Most of VANET applications/protocols are strongly affected by vehicular mobility. Here, we show some research results about mobility influence. We will also introduce how we can synthesize realistic vehicular mobility from simple observations and how we can evaluate its reality. We will also introduce our mobile wireless ah-hoc network simulators for precise evaluation of inter-vehicular communication. Experimental results are also introduced.