Abstract: The theoretic spreading results under an urban scenario with equilibrium traffic are analyzed through modeling mobility pattern, communication channel, medium access control, worm propagation, and others. The extensive Monte Carlo simulations uncover the effects of the transmission range (from a typical minimum to a maximum), the minimum velocity and the maximum velocity (from the free flow to the congested traffic), and the vehicle density (from a sparse topology to a dense spatial relation) on epidemic spreading of such worms in vehicular ad hoc networks. Further, the wireless worm propagation in the same scenario with dynamic traffic is simulated by using network simulation software, the correlation between theoretic results and practical outcome is discussed, and the reasons resulting in the local differences are also analyzed.