Inter-vehicle communications (IVC) based on mobile ad hoc networks have attracted increasing attention of researchers recently. In this paper, we study the communication performance of IVC networks in multilane dynamic traffic streams. We are concerned with the influence of several traffic factors on multilane communications, such as vehicles' high mobility, traffic directions or relative speed, and traffic density. So several simulations were conducted in network simulator 2 with Monte Carlo method for a penetration rate of 10%. The simulation results show that vehicles' high mobility does not greatly affect the communication of vehicles on different lanes; traffic streams running to opposite directions will distinctly affect each other's communication performance, but the unidirectional traffic streams with a relative speed of 30km/h has no obvious impact; under the bidirectional condition, the increasing of traffic density on one lane cannot markedly improve the communication performance of the IVC networks. These results help to better understand the communication of multilane traffic streams under high mobility scenarios.