Fire Department Preemption

As the call comes in and your department is focused on digesting and learning the circumstances of the emergency and the scene while enroute, traffic shouldn’t be a major consideration. Today’s electronically distracted drivers have made the opposite even more true. Motorists already respond to the presence of an emergency vehicle differently but often distracted drivers do not react at all.

Traffic Accidents leading case of Firefighter in line of duty Fatalities

Unfortunately statistics show that nearly half (40%) of firefighters killed in the line of duty die in traffic accidents enroute to the scene. This doesn’t include injuries, civil disputes on who is at fault, damage to equipment and of course a slower response time.

Preemption improves these circumstances. Even when distracted by electronic devices motorists still pay attention to the traffic light via peripheral vision. Preemption is not new, it has been available for decades. However historically it hasn’t really helped that much. Optical Preemption systems are greatly limited by LOS (line of sight) and hence low range therefore not allowing traffic enough time to react to the green light often resulting in only a marginal improvement to safety and response times. These systems are still sold today and still come with a hefty regular maintenance expense.

2.4 GHz WiFi Radio based systems are not the solution

Although newer GPS systems eliminate LOS issues and increase range, some systems use 2.4 ghz (WiFi) and therefore only have a max range of 2,500 feet (.47 miles/.76 km). At busy intersections and/or high traffic areas starting the process of changing the light to green 4 tenths of a mile away will not result in a clear intersection. Often traffic is congested 4 tenths of a mile or more. Traffic lights do not immediately turn green when preempted, first the light in the opposing direction must go from green, to yellow, and then finally to red allowing a green light in the preempted direction. This process can take 5 to 15 seconds. Preemption is also not allowed to override pedestrian crosswalk timers which can increase the time further.

The Eliminator has a range of 13,500 feet (over 2.5 miles/4 km). Where this really matters is when you factor “obstructions” such as curves in the road, valleys and hills, buildings, trees, and other obstructions including the semi or bus in front of you. Obstructions reduce the effective range of a system. Obstructions turn 4 tenths of a mile of other GPS Preemption Systems into 3 or 2 tenths of a mile. One solution is to buy repeaters (also called range extenders). Not only is this more equipment to buy/maintain but also more points of failure. Additionally, extenders create latency that slow up the process.

Is there another obstruction that reduces range that isn’t as “visible”? Yes, other systems using the same radio frequency. The 2.4 GHz band is extremely busy with home and business wifi systems. Even if you buy a newer router for your home that operates at 5.8 ghz it still also operates at 2.4 GHz. This is part of why FEMA recommends preemption systems that use the 900 MHz band instead of 2.4 GHz or optical line of sight (LOS) systems.1

Cellular Systems are not the solution

Just as with Radio/GPS based systems, cellular based preemption systems also solve the line of sight (LOS) problem, however these cellular emergency vehicle preemption systems bring a new set of problems.

  • Cellular brings monthly fees. Imagine a coin operated box attached to the signal and every preemption having a cost. More specifically and costly, every communication, resulting in a preemption or not, will have a cost. 
  • In large emergencies (mother nature, terrorism, etc.) the cellular network always go down. So when you need your preemption the most it will not be functional. 
  • Are Cellular networks 100% reliable? Anyone with a cell phone knows they are not. From lag/delay to network overload you do not want your green light being dependent on a network shared by everyone else around you. 
  • Although some cellular systems may offer a radio backup, it is just that, a backup. If the radio backup worked well then it wouldn't be the backup. When these systems are proposed in a bidding process they are required to include 10 or even 15 years of unlimited cellular data.
  • Since cellular based preemption lacks precision the preemption timings will not be precise or consistent which degrades performance and benefit. Recently one large city tested a cellular preemption system and found it took up to 10 seconds to release a preemption. This can result in the preemption being held for a tenth of a mile or more after the EV clears the signal.


It is also worthy to note that using 2.4 GHz and Cellular go against FEMA recommendations for Preemption Systems.1.

Reducing the number of lights/siren responses

While reducing the number of lights and siren responses undoubtedly reduces the chances of the apparatus being involved in a collision, this policy may not be practical in some situations. In particular, companies that operate in extremely congested urban settings may need to operate their lights and sirens to clear slow or stopped traffic in order to prevent long out-of-service times while responding to minor incidents. In these cases, although the incident may not necessarily warrant an emergency response, excessive out-of-service times might prevent them from being available to respond to a true emergency. In these situations, drivers should use a modified emergency response - using warning devices to clear a reasonable path to the incident, but not operating the apparatus with the sense of urgency used when responding to a true emergency.2

The Eliminator’s “ON MODE” feature has the unique ability to facilitate such a “modified” emergency response (See Fire Chief Danny Sink Video for more information on this and other features). By preempting traffic signals WITHOUT the use of lights or siren, the chances of the apparatus being involved in a collision are dramatically reduced, while the travel time is similarly reduced by 14% - 23%.3 This eliminates excessive out-of service times that might prevent them from otherwise being available to respond to a true emergency.

Improved response times can lead to an improvement in the insurance industry ratings of a community’s fire suppression service, with a corresponding reduction in fire insurance rates for residential and commercial property owners. The Insurance Services Office (ISO), through its Public Protection Classification (PPC) program, assigns insurance ratings to each participating community once every 10 years.4 By classifying a community’s ability to suppress fires, the ISO helps the communities evaluate their public fire protection services and planimprovements. The ratings are very important to communities as they pursue growth and economic development plans. Some communities, such as the Town of Blacksburg, Virginia have reported that its ISO Class had been raised reflecting the response time improvements made possible by EVP deployments.5

Meet the Firefighter/Engineer that designed our Preemption System.

However, being a firefighter is only half the story, Adam has spent over a decade designing systems for defense contractors that use Radio and GPS. He knew from his diverse experience that existing GPS, Optical and cellular Traffic Signal Preemption System weren't meeting the two most important needs, affordability and performance.

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GPS Preemption Compatible with Optical

Do you already have an Optical Preemption System or Infrared Preemption system or commonly referenced by a brand name such as Opticom ®, Emtrac ®, Tomar ®, Strobecom ® or MIRT ®? Upgrading to a GPS Traffic Signal Preemption System is affordable and simple.

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FireRescue1 Industry Article

Could traffic preemption reduce fire response times and save lives? Once overlooked as expensive and impractical, signal preemption has come a long way since the 1970s

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Fire Departments

As the call comes in and your department is focused on digesting and learning the circumstances of the emergency and the scene while enroute, traffic should not be a major consideration. Today�s electronically distracted drivers have made the opposite even more true. Motorists already respond to the presence of an emergency vehicle differently but often distracted drivers do not react at all.

Learn More

Police Departments

The Eliminator Emergency Vehicle Preemption (EVP) System provides specific features designed for Police Departments. Most EVP systems use ETA or GEO windows to define when or where preemptions occur. However Police Cars typically travel at a higher rate of speed than Fire and EMS, specifically faster than the larger vehicles such as Engines, Tankers, and Ladder Trucks.

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From the moment an emergency run begins, there is potential for an even greater disaster; colliding with another vehicle enroute to the scene of the emergency. This often results in that vehicle and its occupant(s) becoming an additional emergency incident to address. Many cities have experienced an increase in collisions with emergency vehicles at intersections, but emergency vehicle preemption has been shown to effectively reduce the probability of these collisions by giving ambulances the right of way.

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