The availability of automatic crash notification (ACN) systems is increasing. First generation systems that are available today provide crash notification and vehicle location in the event of a frontal crash in which airbag deployment occurs. Advanced systems will soon be available that are capable of detecting a variety of crashes and reporting the character and severity of the crash. An as yet uninvestigated area concerns how ACNprovided information can be used effectively by the emergency medical services system. Of particular interest is the potential synergy between advanced ACN systems and more effective utilization of helicopter emergency medical services (HEMS) for trauma scene transports. This paper reports on the patterns of ground ambulance and HEMS trauma scene transports for patients injured in motor vehicle crashes that occurred in Erie County, New York. These data were used to determine if observed transport patterns were consistent with areas previously identified as the most time efficient for trauma patient transport by HEMS. Additional analyses were conducted to determine the potential effect of ACN data on the definition and refinement of areas identified as the most time efficient for HEMS transport. In particular, the transport data timelines were examined to identify the affect on total prehospital time of putting the helicopter on standby based on the more timely crash notification and severity information provided by advanced ACN systems.