Police Department Preemption

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. Therefore optimal settings used for a Fire Engine that travels 40 mph will not be optimal for a Police Vehicle that can be traveling as high as 70 or 80 mph. Seemingly ETA should equalize these two vehicles, however the traffic signal takes a fixed amount of time to cycle to a green light and civilian traffic takes a fixed amount of time to react therefore reducing the impact of using ETA. GEO Windows are even less flexible in that they will always preempt at exactly the same place.

The Eliminator provides several features that are key to optimizing preemption performance for all departments and vehicles. 
  • Preemption settings can differ by department, therefore allowing the police department to have different settings tailored to their vehicles that travel at a higher rate of speed and are more maneuverable. 
  •  Each department gets two classifications of preemption settings. One for light duty vehicles (typical first response vehicles) and one for heavy duty vehicles that are larger, travel at a slower rate of speed, and are less maneuverable.

With other preemption systems one common complaint is that the preemption route can be “over driven”, which means if you drive too fast you will drive faster than the system can respond. This is an obstacle caused by several factors:

Other systems have a much lower radio range than the Eliminator. Other systems have a range of 2,500 to 3,600 feet which is only several tenths of a mile. Additionally some systems use cellular communication that comes with latency (delay) and your system becomes vulnerable to the state of the cellular network. Some systems actually use WiFi 2.4 GHz which leaves your system vulnerable to an extremely congested and low ranged radio band that is also used by residential consumers. 2.4 GHz and Cellular networks are known to be congested and not 100% reliable. When it comes to Preemption, reliability is crucial. Additionally, in the event of a larger emergency, these networks will be further taxed by civilians further reducing the performance of the system.

Using the commercial 900 MHz FHSS (Frequency Hopping Spread Spectrum) ISM (Industrial Scientific Medical) band overcomes these obstacles, and also allows for “omni-directional” communication with other emergency vehicles, the ideal platform for the Eliminator’s patented v2v (vehicle to vehicle) collision avoidance system. It is also worthy to note that using 2.4 GHz goes against FEMA recommendations for Preemption Systems.1. The Eliminator has an unmatched 13,500+ feet range.

The research overwhelmingly points to the fact that risks, to both the community and first responders, will be reduced after the implementation of an Emergency Vehicle Preemption System at signalized intersections. This reduction in risk can be measured by the reduction in accidents and injuries occurring at intersections controlled by preemption devices.2

The Eliminator uses the commercial ISM (Industrial Scientific Medical) band with a radio range of over 13,500 feet, several miles. This increased distance allows greater flexibility to proactively preempt the traffic signal in the safest and least disruptive way possible and allows the flexibility to adapt to the different needs of Fire, Police, and EMS including the differences in their fleets.

Although the Eliminator Preemption System can connect via WiFi, Direct Network (RJ45) and Cellular these connection protocols are only used for management, log retrieval, AVL (Automatic Vehicle Location), and other similar purposes. Although we can trigger preemption using these methods, it is not recommended.

In the field we often hear the concern regarding “abuse” of preemption. This involves using the system to preempt the traffic light while not on an emergency. The Eliminator prevents this abuse via configurable settings. The system can be configured to only preempt when on a hot run and cannot be overridden. Further all preemption's are logged and tracked at the traffic signal and the vehicle. This provides full accountability.

Nationwide, over the past 10 years, more than 25 percent of all Emergency Vehicle crashes have been found to occur at signalized intersections.3 These crashes often involve situations where vehicles approaching a green signal cannot see an Emergency Vehicle approaching on the intersecting roadway because of line-of-sight problems with nearby buildings, vegetation, or hills. For these situations, Emergency Vehicle Preemption provides familiar guidance to private vehicles by showing a red signal at the conflicting approaches, thereby bringing these vehicles to an orderly stop. Safety benefits can be measured by comparing EV crash histories or, as a surrogate, by measuring the reduction in the number and severity of conflict points that may be present at the time when an Emergency Vehicle traverses the intersection.4

A decrease in Emergency Vehicle crashes reduces public liability associated with fatalities, injuries, and property damage. Over the past 10 years, there have been approximately 80 EV crashes each year in the U.S. that involve fatalities.5

As in the fire and EMS services, there exists no national standard or regulations for police agencies about when or when not to respond to calls using emergency driving procedures. While there may be some direction from applicable state motor vehicle codes, most policies that exist on this topic are agency-developed and highly dependent on the culture of each individual department. In many cases, the policies that are in place are not highly specific on when and when not to drive in an emergency response mode. This is because of the perception that every call is a different situation and certain variables may or may not justify an emergency response.

In reality, all law enforcement agencies should have relatively firm policies on what justifies an emergency response and what does not. There must be some flexibility in these policies to account for conditions such as inclement weather, heavy traffic conditions and other factors that may influence the response time. However, in establishing these policies, law enforcement agencies should use a risk versus benefit perspective to determine when emergency driving is appropriate.

One of the critical factors to consider when developing this type of policy is whether there is any likelihood that a slightly faster arrival on the scene of call is likely to make a difference in the outcome of that incident. Many, if not most, incidents that police officers respond to are actually over before the caller even talks to the 911 dispatcher. In those incidents, an emergency response versus a non-emergency response will make no difference in the outcome.6

The International Association of Chiefs of Police (IACP) has developed a set of model policies and procedures that can be adapted by local police agencies for use in their jurisdictions. “The Manual Police Traffic Services Model Policies and Procedures” can be downloaded from the Internet at no charge.7

The Eliminator’s “ON MODE” feature has the unique ability to facilitate such a “modified” or non-emergency response (See Fire Chief Danny Sink Video for more information on 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.

U.S. Fire Administration, Emergency Vehicle Safety Initiative, FA-336/February 2014, page 100, Download PDF

2 Reducing Risk Through the Use of Traffic Preemption, Mark A. Lorenzen, VenturaCounty Fire Protection District, Camarillo, California, page 29, Download PDF

Traffic Signal Preemption for Emergency Vehicles, A Cross-Cutting Study, Putting the “First” in “First Response”, FHWA (2006), page 3-1, Download PDF

Traffic Signal Preemption for Emergency Vehicles, A Cross-Cutting Study, Putting the “First” in “First Response”, FHWA (2006), page 3-1

Traffic Signal Preemption for Emergency Vehicles, A Cross-Cutting Study, Putting the “First” in “First Response”, FHWA (2006), page 3-1