IMSA Journal 2007

A Paradigm Shift In Traffic Signal Preemption

BY Dave Gross, President/CEO Collision Control Communications, Inc.

Collision Control Communications, Inc. is pleased to introduce a cost effective emergency vehicle preemption system that represents a paradigm shift in traffic signal preemption technologies. The Eliminator™ is a patented radio based system and its components will be on display for the first time at this years IMSA Louisville convention in August. Based on seven years of research and development by professors at Indiana University/Purdue University and J & S Resource Management, this technology has many significant advantages over systems which are currently available. The most notable life saving advantage is collision avoidance. In the event two or more emergency vehicles are on a collision course, the Eliminator™ warns the driver of each vehicle of the impending collision both audibly and visually, giving the relative direction of the impending threat.

Collision Avoidance

A circular ring of 60 LED’s on the face of the vehicle unit alerts the driver to the direction of the impending collision, displaying its angle of incidence with an accuracy of + 3 degrees (see figure 1). In the event of a collision impending from the right at a 90-degree angle as in the example shown in figures 1 and 3, a pre-recorded female voice will also warn the driver with the audible cue “collision alert at 3 o’clock”. The Eliminator™ is capable of mathematically calculating and displaying up to sixty different impending collisions simultaneously.Collision alerts are presented at both signalized and non-signalized intersections, including alleyways and even rural areas where the nearest traffic signal may be miles away. Collision avoidance data is securely transmitted among wireless AeroComm™ transceivers utilizing frequency hopping spread spectrum broadcasting in the 902.217 – 927.492 MHz frequency range. The Eliminator’s™ distance-to-collision sensitivity can be adjusted from less than fifty feet to up to one mile.


Traffic signal preemption is effectuated utilizing a wireless directional signal in the 2.4 GHz spectrum. Preemption trigger distance can be adjusted “on the fly” to up to three quarters of a mile, if desired. Unlike infrared/optical preemption systems, the Eliminator's™ capabilities are not limited to “line of sight”. Preemption is easily triggered irrespective of visual obstructions such as semi-trailers, buses, bridges or overpasses; it works equally well where visibility is reduced by heavy fog, snow, rain or blowing sand/dust. While GPS preemption systems have overcome many of these drawbacks, most need to be “taught” to learn when the vehicle has entered an area where preemption is desired. The Eliminator™ has no such “learning curve” and is ready for use immediately upon installation.

GPS units, by technical design, also require satellite triangulation to know “where they are”. This is not always possible at intersections in large cities where one or more skyscrapers, for example, may preclude satellite triangulation. The Eliminator™ vehicle unit acknowledges preemption confirmation to the driver by changing the “status” light on the face of the device from red to green. Preemption by the vehicle units can be used in two different modes: auto mode (also referred to as “hands free” or “smart” mode) and manual mode. In auto mode, traffic signals are automatically preempted whenever the light bar is activated. Preemption is automatically disengaged when the vehicle arrives on scene, irrespective of light bar status. This mode allows the operator to “set it and forget it”. Upon arrival at the scene of an incident, it is often necessary for the operator to exit the vehicle expediently and begin rendering assistance, without having to remember to shut off the preemption feature. It allows preemption to be automatically relinquished from vehicles that are stationary at the scene with light bars activated to those who are still approaching. This mode is also particularly useful for a motorcycle police officer, since he would not have to remove his hands from the handlebars to operate the system. In the “manual” mode, preemption is always active. One use for manual mode would be an unmarked police unit that may desire preemption, but not want to announce its presence by lights or siren.

As intelligent transportation systems evolve, many of them will require the exchange of real time traffic data over greater distances. Since the traffic signal transceivers in the Eliminator™ system (see figure 2) have the ability to wirelessly and securely relay the throughput of additional data up to one mile, the technology is also uniquely poised to be able to additionally become the architectural “backbone” for many of these intelligent transportation systems currently being designed.

Figure 1.
Face of the emergency vehicle component of the “EliminatorTM” systemCAD rendering courtesy Mark Ramsey

Figure 2.
TS-2 Traffic signal cardPhoto courtesy Steven Zavodny

Figure 3.
Emergency vehicle component of the “EliminatorTM” system showing collision impending from the right at a ninety degree angle (3 o’clock position)

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.

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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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