Lights and Sirens and Safety

lightsandsirensThe use of  lights and sirens is supposed to clear traffic by warning drivers or pedestrians that a public safety vehicle is approaching in emergency mode. The expectation is that the use of warning devices increases the safety of both the patient and provider by reducing travel time in responding to a scene or while transporting a patient to the hospital. Conceptually, this visual and audible cue is requesting that other nearby motorists yield the right-of-way to the approaching ambulance.

While lights and sirens are a fundamental cannon of every agency’s standard operating guidelines, their efficacy has never been proven to positively impact patient outcomes. To the contrary, there are examples nearly every day of the failures of these warning systems to provide a safe transport. Just last night there was an accident as an ambulance broke an intersection in Orlando and a few days earlier another crash was reported in Chicago. And literally as I was writing this post, an ambulance from a small town in New York was also hit at an intersection. If warning devices worked, why do we see so many accidents?

In our current age of evidence-based clinical practice, it is more than fair to question operational procedures as well. Studies have shown full use of lights and sirens decrease hospital transport time by only 18 to 24 seconds per mile when the ambulance trip is less than five miles – and there is virtually no time savings at all when the transport is over five miles. Additionally, studies show that the operation of ambulances with warning lights and siren is associated with an increased rate of collisions.

According to a 2010 report on EMS Highway Safety by the National Association of State Emergency Medical Services Officials, “no evidence-based model exists for what ‘mode’ of operation (lights and sirens) should be used by ambulances and other EMS vehicles when dispatched and responding to a scene or when transporting patients to a helicopter landing zone or hospital. A New Jersey based EMS provider, MONOC, has produced a video that aims to protect EMS providers through creating a culture of safety and limiting the times that warning devices should be used. We do know accidents happen when lights and sirens are used. We also know they save very little, if any, time in transport. But no one wants to completely eliminate them. They are in about the same position as the long spine board. We shouldn’t use them as much as we do, but they seem to still have a proper limited space of operation.

In attempting to limit their use, we can come up with some crazy ideas. A new protocol affecting 15 West Michigan counties calls for the use of emergency lights and sirens only to “circumvent traffic,” primarily at intersections, by ambulances transporting patients with life-threatening conditions. Once traffic has been circumvented, lights and sirens are to be turned off. This seems potentially dangerous  as drivers have less warning of an approaching ambulance leaving less time to react. In my experience, drivers are already confused on exactly what they should do when they finally realize we are in a hurry behind them. My other personal concern would be the impression left with drivers when the lights and siren are switched off after “circumventing the traffic.” Will the public incorrectly view the situation as an abuse of the “privilege” to run emergency traffic just to clear traffic? In researching some of these questions, I ran across a serious question from the public asking “if the guy dies do you turn off the siren?” We have failed as an industry to teach the community what we do and how we do it.

The article, “Why running lights and sirens is dangerous” discusses not only the issues faced, but proposes steps that should be taken to reduce the risks associated with driving ambulances “hot.” One objective for safer operation is to reduce the miles that ambulances travel under lights and sirens. The Michigan protocol attempts to accomplish this objective by requiring them to be switched on and off throughout the trip, but another alternative is to change the starting point of an ambulance prior to responding to a call. Many services already accomplish this through dynamic deployment to hot spots of forecast demand which has shown to be effective in reducing both the distance traveled in emergency mode and reduces the overall response time as well.

Carefully consider, within your protocols, when to use the warning devices available to you. Never assume that they “grant you” any right-of-way, as they can only request motorists yield it to you. It is always your obligation when operating an ambulance to drive cautiously for your own safety as well as the public. You can change the culture of ambulance operations to prevent accidents and be safe!

5 Comments

  • BHelland says:

    Overall, I’m in agreement with the author, and with many other authors who are focusing on safety in fire and EMS. However, we must be careful when we start citing “studies” to prove our evidence based practice, whether operational or clinical. In the citations above, only one is from a peer reviewed journal. That study admittedly used a survey with only 4 questions to survey the opinions of EMS responders. The author then makes the claim that “the operation of ambulances with warning lights and siren is associated with an increased rate of collisions.” If you read the cited study, that is not what the authors concluded.

    The article written by Sanddal, et. al. was a retrospective look at a website that copied newspaper articles as its source of information. You cannot find a poorer source of information for “science” than reading a newspaper article for details.

    While I agree with the concept that we need to focus on what works, what doesn’t work and what needs improvement, we also must read with a critical eye and avoid the notion to jump on the bandwagon because everyone is doing it. To further our profession, we need to be credible.

  • bennea says:

    The key to safety while responding emergency is mentioned in the second to last sentence in the article. From what I’ve observed in 25 years in fire and EMS, accidents happen when the driver of the emergency vehicle is not driving cautiously. The Public are not driving around waiting for a chance to yield to an emergency vehicle. They are thinking about work, school, what to eat for dinner, and etc. Basically, everything but emergency vehicles. For this reason I try to teach new firefighters to slow down when driving emergency. Especially when approaching intersections. It gives preoccupied drivers more time to react, and although the emergency responder is driving slower, people have that much more time to react, and things go more smoothly, thus faster.

  • Dan Bishop says:

    I appreciate the comments and the issue as well. It largely mirrors what I have seen with years in this service and unfortunately not a lot of evidence supports either case. The key is continued optimization of both the deployment and policies applied within dispatch and operational practice. By reducing the need for lights and siren use through prioritization of calls and the optimal deployment of resources risk can be reduced dramatically.
    Optimizing practice along with effective communication to both staff and the public are key to your strategies.

  • Gary says:

    I’ve been in the fire service for over 40 years (as a volunteer ) and have only had one close call. That was on a narrow rural road when I overtook a motorist, having nowhere to go when seeing my emergency lights, did a frantic emergency stop just a few yards ahead of my engine. Had I been running the allowed “code” speed there would have been a serious collision.
    Over the years, both as Station Captian, Training and Safety Officer, I’ve stressed “Get There Safely! You can’t do any good if you are delayed in an accident”.

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