No one likes to be stuck in traffic. Time is money, after all. But what represents an inconvenience or even loss of income for most of us can turn into a much more serious loss for emergency response workers.
Traffic doesn't just cause a delay for emergency responder. It can cause fatalities as drivers collide with emergency vehicles at intersections. Between 20% and 25% of firefighter deaths are the result of traffic collisions, according to the United States Fire Administration (USFA), an agency of the Department of Homeland Security. Those deaths may be prevented with the help of emergency vehicle preemption (EVP) systems. Aside from saving lives of emergency responders, such systems can preserve the lives of those they go to help by cutting down on the time it takes to get to the emergency and deliver people to safety. As we saw in Analytics Speed Up Response Times for EMS, minutes can mean the difference between life and death.
Perhaps an EVP system that analyzes an emergency vehicle's GPS coordinates could help to safely speed response and services. All EVP systems depend on a traffic light responding to a signal for priority treatment for the emergency responder, and a few different systems are currently in use in US communities where traffic conditions can seriously impede an emergency response vehicle. In New York, Assemblyman Phil Goldfeder is pushing for such a system to be installed in southern Queens, particularly in the somewhat isolated Rockaway area. I emailed him to ask about the technology, and he put me in touch with Dennis Graham, one of the founders of the Center for the Study of Healthcare Delivery (CSHD).
Graham sent me quite a lot of material about the subject, including a report entitled, "Emergency Medical Care in the Rockaways," with the motto "Where you live should not determine whether you live." The report explains that, in the absence of data about how long it takes for emergency responders to get patients to a Level I Trauma Center (LITC), its creators came up with figures based on Google Maps directions. It compared the Rockaways to other areas in Queens. The research found that at best it took 26 minutes to get to a hospital from the center of the Rockaways. During rush hour it took 48 minutes. Those numbers represent significantly longer travel time than for the rest of Queens, where hospital runs average less than 15 minutes outside of rush hour.
He believes that an EVP system offers a feasible solution to the problem of controlling traffic lights. The report reviews the three EVP system systems to explain why a radio-based GPS solution is the best option.
There are systems based on acoustics, in which a traffic light's sensors pick up on the sirens for their signals. The disadvantage of that is that they are sometimes set for the wrong direction or placed in the wrong intersections.
A second way the system can work is by line-of-sight. That’s what the Manhasset-Lakeville Fire Department set up with LED lights on emergency vehicles that trigger the traffic lights to turn green for their direction as they approach an intersection. The disadvantage of that system is the high cost of hardware that has to be installed on both the vehicles and on the traffic light controls. The system is also not completely secure, since the preemption hardware can be forged.
The third type of system works on localized radio signals. While it also entails an investment in hardware, it seems to be the most reliable, according to Graham. To obtain reliability with maximum economy, he favors a GPS system that sends signals over the Internet.
It saves on the hardware cost by capitalizing on what is already built into mobile devices. An open source Arduino microcontroller at each traffic intersection with an Ethernet Shield connects to the Internet. Such a system calls for the components highlighted in this graphic.
Each traffic intersection would need an Arduino microcontroller with an Ethernet shield to enable it to connect to the Internet. Each ambulance would have a staff member carrying an Android application on a smartphone to receive GPS coordinates and transmit the same to a Web server. A Web server receives the GPS coordinates of the emergency vehicles and sends preemption signals to traffic signal controllers according to their position and movement.
Graham points out that a GPS system already was a proven success in Savannah, Ga. Before the system was deployed in 2007, it took as long as seven minutes for emergency vehicles to get through the DeRenne Avenue corridor. The time was cut to just over a minute. That's very clear improvement on time that can make a crucial difference to the survival of patients, and also keep drivers safer from collisions. It's all definitely a win-win.