Abstract: Link dynamics of vehicular ad hoc networks (VANETs) have great difference with that of the traditional mobile ad hoc networks (MANETs) due to the impact of simulation scenarios. Based on Manhattan mobility model, the influence factors of vehicular nodes in urban environments are analyzed, including traffic light and drivers’ behavior. Analytical expression of expected link lifetime is derived. The impact of traffic light and drivers’ behavior to the expected link lifetime is analyzed. The simulation results verified the accuracy of the analytical results.