Traffic safety applications using vehicle-to-vehicle (V2V) communication is an emerging technology and promising area within the ITS environment. Many of these applications require real-time communication with high reliability; to meet a real-time deadline, timely and predictable access to the channel. The medium access method used in 802.11p, CSMA with collision avoidance, does not guarantee channel access before a finite deadline. The well-known property of CSMA is undesirable for critical communications scenarios. The simulation results reveal that a specific vehicle is forced to drop over 80% of its packets because no channel access was possible before the next message was generated. To overcome this problem, we propose to use STDMA for realtime data traffic between vehicles. The real-time properties of STDMA are investigated by means of the highway road simulation scenario, with promising results.