Limitations
Given our goal of creating a tool based on Google Maps, it would have been ideal to derive our transport time estimates from Google Maps; however, the Google Maps licensing agreement prohibits submitting large batches of addresses through their website for route generation, requiring us to estimate transport time and distance using the ArcGis Network Analyst. Our demonstration application complies with the Google Maps licensing agreement, as it generates routes one at a time. We expect estimates from Google Maps would be more accurate than those we derived, as Google Maps makes use of live traffic data.
The refinement of technologies that can be marketed to billions and adapted to EMS will far outpace that which is produced exclusively for use by emergency responders. Unfortunately, the rapid progress in consumer mapping guarantees that today's publications report on yesterday's technology. In addition, commercial secrecy limits our understanding of the how these applications work and leaves those who develop end-user applications at the mercy of those who create the underlying technology. Developers of applications that are mission-critical to EMS systems will need to consider the reliability of internet-based technologies. Confidentiality issues are also a concern, as the Google Maps API requires sending location data, which is potentially considered to be protected health information, to Google's servers for processing.
Conclusion
Ambulance location data and a simple web-based application can be used to provide accurate estimates of ambulance time of arrival to the emergency department, which could be applied to improve emergency medical resource use. Use of lights and sirens was related to a greater savings in transport time than previously reported.