Electronic Traffic Control to Speed and Safeguard Fire Force Response

Electronic Traffic Control to Speed and Safeguard Fire Force Response


As Columbia, S. C., apparatus approaches intersection, the officer notifies the dispatcher by radio and the traffic lights and corner siren are operated for clearance.The fire alarm operator may remotely control all the city traffic lights and corner sirens from a single point. After the apparatus clears an intersection, operation in the normal manner is restored to the corner controller

—Photo courtesy General Klectnc Company

Experiments indicate drivers of emergency vehicles can control street traffic signals from their moving vehicles, at a distance. It’s all done by short wave radio


OVER THE YEARS, traffic accidents involving fire apparatus have not only proved costly and disabling to fire departments, but have unnecessarily endangered the lives of firemen responding to and returning from fires and other emergencies. Such accidents have caused serious delays in response of fire forces which in turn, proved costly in terms of lives and property endangered.

Many accidents involving fire and other emergency vehicles have been recorded in the pages of FIRE ENGINEERING, together with the measures being taken to reduce the toll and the cost. But notwithstanding all efforts, including stiffening of penalties for traffic violators, the number and severity of these accidents continue to mount.

Operators of fire department vehicles have not always been blameless in this carnage. Many accidents have been the direct result of “carelessness, unconcern, heedlessness and downright negligence,” according to Fire Chief Edward J. Blohm of the Detroit Fire Department.

If any city in the country should be familiar with the problems of automotive traffic hazards and control, it is the “Automobile City” of Detroit. Nevertheless so serious has this situation become that the fire commissioners and Chief Blohm have issued orders that apparatus shall be brought to a complete stop on approaching any intersection with either a changing light or a red fight against them, a stop street, or a railroad crossing not equipped with flashing warning signals or a warning gate.

In his directive to the department, Chief Blohm said, “Modern vehicles with high powered engines providing unprecedented speed and acceleration, coupled with ever increasing traffic volumes, congestion, great numbers of inexperienced or excitable drivers who become confused or panic upon the sound of approaching sirens or flashing warning fights, make it necessary that this department reappraise our practice in dealing with traffic while responding to alarms.”

Further he points out, “Existing local and state traffic laws and regulations governing fire apparatus responding to emergencies do not protect the driver or the city from the consequences of a reckless disregard for the rights and safety of others.”

He pointed out that “recent court decisions in Michigan have held drivers of fire apparatus liable and responsible for reckless driving.”

Detroit is not the only municipality to reappraise its response problems in the light of present and increasing traffic hazards. All of which emphasizes the vital need for some method, system, or device, for making safer and swifter the response of fire and other emergency vehicles.

As another prominent lire chief said, “What does it avail us to clip seconds off fire detection and alarm transmission and to speed getting out of our quarters and underway for the emergency, if we are going to have to set our pace with the slowest traffic, or else step on it and take chances of serious accidents?”

Search for a system

From the introduction of the first elec trically-eontrolled traffic lights the fire service has found its traffic troubles multiplying. The traffic laws may give fire apparatus the right of way, as they do in most states, but the mortality tables show that laws and regulations alone cannot and will not safeguard response of personnel and equipment. Something more than regulations must be added if maximum safety is to be had.

Over the years public safety officials have searched for that “something.” Nearly all cities have either experimented with, or have adopted some form of control designed to clear the way.

Unfortunately each such experiment up to the present time has introduced certain new problems even while helping to alleviate the previous traffic headache. As modern traffic congestion increases day by day, the weaknesses and drawbacks of the older control systems become more apparent.

There are two general types of central traffic controls of particular interest to the fire service. They are:

  1. Wired control—Essentially a remote switching of either the central master controller or of intersection controllers. The method can be applied to the traffic lights in a pattern designed to meet the needs of the community. By throwing the proper switch all lights in the desired area can show the emergency signal, either in a continuous route or in a “blanket” pattern. The mechanical operation of switching signals is done by the headquarters dispatcher or a station fireman before leaving quarters.
  2. Wireless control—While similar in operation to the wired control, the use of radio eliminates the wire connections necessary in the former. Electronic tone signals are transmitted to the intersection controllers which are equipped with receivers designed to respond to the tones. By selecting the proper tone codes, the desired route of control can be set up by the dispatcher. Operation of such electronic systems may be by central station dispatcher or other remote control.

The most recent system, described in detail later on, is the driver-operated control for which high hopes are advanced by some authorities.

Operation of both wired methods is similar. In case of an alarm of fire, the dispatcher may set all signals red, or yellow, as has been predetermined. In some present installations this may be over common routes which fire apparatus would normally follow in response to certain areas.

The shortcomings of both of the methods are readily apparent. The length of time the signals must remain under control of the “pre-emptor” (even though automatically returned by a time-delay relay) is determined by the distance and the time required for the apparatus to clear the controlled lights. In some cities this may be inordinately long with the result that traffic congestion builds up, sometimes in areas far remote from the actual emergency.

Another, and far more serious, drawback is the dangerous possibility of apparatus simultaneously approaching a controlled intersection from two directions. With the present noise levels of average communities added to the warning siren on each apparatus, it is practically impossible to expect the driver and officer of one piece of apparatus to hear the approach of another from a converging street.

Some departments have attempted to rectify this possibility by specifying definite routes of response for each company. But it has been proved that even this cannot overcome the hazards of enforced route changes necessitated by street construction or delayed response. Multiple alarm apparatus that may be operating in areas not commonly familiar to all the personnel poses an additional hazard.

Diagram of a typical radio-controlled operation of corner traffic signal. An impulse from one piece of fire apparatus has placed the intersection under control of the pre-emptor while the signal from a second vehicle has caused the apparatus warning light to flash a danger signal to the converging driversAerial ladder entering a radio-controlled intersection. The apparatus warning light can be seen suspended near the elevated traffic signal. In case a second piece of apparatus approached the same intersection, the flashing light would warn the driver of the danger

—Photo courtesy Eagle Signal Corp.

In a number of cities these predetermined response streets or lanes have been designated by signs so that local and visiting motorists may be governed accordingly. Other cities have indicated these routes by both signs and sirens. However, these expedients have been only partially beneficial. Motorists apparently continue to wend their own inimitable, thoughtless ways.

Although only indirectly related to the question of traffic signal control, nevertheless one experiment being undertaken by several cities, including New York, offers some hope of benefit. This is the establishment of fire lanes on one-way streets. These lanes are usually in the center of the roadway, and are marked off by yellow or some other special color designation. Upon hearing siren and/or bell, the drivers of vehicles are expected to immediately swing into other traffic lanes, thus providing a clear path for the responding fire apparatus. This experiment is being watched with interest and FIRE ENGINEERING will later bring its readers the results of the installations.

Visual and audible warning

Many departments have experimented with methods of remotely controlling traffic lights at individual intersections. The use of “corner sirens” to give advance warning of the approach of apparatus has been added in some cities to further expedite the response. Coupling the audible siren with the abrupt change of the visual signal is felt to be an unmistakable indication to the motorists and pedestrians which results in greater safety for all concerned.

Columbia, S. C., installed this type of control several years ago. As reported in the December, 1952, issue of FIRE ENGINEERING, it consists of an operating panel containing remote control switches for each of the city’s 88 traffic lights. The first responding apparatus notifies the dispatcher of its approach to an intersection by means of the mobile radio unit. The dispatcher then changes the signal indication to “flashing amber” and the corner siren sounds a simultaneous danger signal. After the fire truck clears the intersection the dispatcher is notified bya radio signal and he remotely returns the signal to the intersection controller by restoring the panel switch to the “off” position.

This method of control has the advantage that only the intersections concerned need to be controlled and apparatus arriving from a cross-street have both visual and audible warning (from the radio) of possible danger. However, the extensive cable requirements and physical operating limits of the controls of this system pose problems for some of the larger cities.

Electronic signal control

In recent months several methods of mobile radio control of traffic signals have been advanced to solve the problem. Two of the representative systems use a unique application of radio to control vehicular movements at individual street intersections with the added highly essential safeguard of visual indication to the apparatus drivers that the system is operating, and that fire or other emergencyvehicles may be approaching the intersection from a side street.

The advantages of this new “spot” method of traffic regulation are readily apparent. The control of the system is vested in the operator of the vehicle that is approaching the intersection and not by some operator at a distance who is totally ignorant of the local conditions being encountered by the various responding units. Only the signals at the intersection immediately ahead of the vehicle are affected and traffic stoppage is centered at a single point. The length of time required for vehicle clearance of the intersection is only a matter of seconds, allowing quick resumption of traffic flow.

Perhaps the most important advantage of the revolutionary idea is the warning given by certain of these systems when two emergency vehicles approach the same intersection from cross-streets. Immediately a signal light starts flashing out its message of danger to the drivers. It is easy to visualize how great a safety factor such an operation can be to firemen responding to an alarm.

The compact, highly directional vehicle antenna used by one manufacturer projects a signal about one-quarter of a mile in front of the vehicle with a width of 200 feet

—Photo courtesy Electronic Protection, Inc.

Equipment function

The operation of the representative systems are similar in detail. All vehicles required to respond on emergency service are equipped with a small radio transmitter and a directional antenna. The mobile unit operates in the UHF (ultrahigh-frequency) region of the radio spectrum and has an effective range of about one-quarter mile. The highly directional antenna designed for mounting on the hood, projects a narrow signal beam forward of the vehicle. The narrow beam prevents the transmitted signal from interferring with the traffic lights that maybe located on parallel streets, and the low power allows only those lights immediately in front to be controlled, thus effectively preventing traffic jams in unwanted areas where control may be unnecessary.

Operation of the unit is by means of a switch located on an operating panel which can be conveniently mounted under the dash of the vehicle. As the driver approaches the intersection, he presses the control switch and the signal is transmitted.

The actuating signal is projected to a receiving antenna mounted on or near the traffic light controller. This signal is in turn picked up by a small receiver located within the controller housing and is passed along as an impulse to a preempting relay which automatically takes over control of the intersection lights in a predetermined method. Upon passage of the apparatus, the lights are returned to the supervision of the controller. An adjustable “hold” relay can be preset at any reasonable time for this return cycle.

Should two vehicles approach the same intersection at the same time, a warning signal light immediately begins flashing a visual signal to the drivers that caution must be exercised.

Minor differences of systems

The operations of the present representative systems are almost identical in detail. However, there are a few minor variations that may be important for some areas. Both systems are very flexible and the traffic lights can be set to operate in any given pattern as desired.

In one system, a special light known as an “interrogation” light faces each traffic lane. When the radio signal is transmitted and received by the traffic controller, the interrogation light is actuated and this notifies the driver by its steady glow that the system is under control of the radio signal. If two vehicles approach the intersection from converging streets, the interrogation light facing the first vehicle remains steady while the light facing the second vehicle flashes a continuous warning to indicate that caution is necessary.

In the second system, the sequence of operation can be adjusted to suit the operating requirements. In one city presently installing the system, all traffic lights on the intersection flash a yellow caution light as soon as they arc activated by radio. This warns the motorist of an impending change from normal operation and at the same time signals the emergency vehicle operator that the system is under control. After a few seconds of the flashing lights, all signals turn red in this system, as in the other. If two vehicles are approaching the same intersection, a separate flashing red light begins operation, warning both drivers to exercise caution.

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The adaptation of any one of these electronic devices to the ever-growing and complex problem of traffic control promises to bring a new standard of safety to the fire service. In the past, all methods of approach have been from an inflexible central point operated by a dispatcher who had no visible means of judging the conditions. These new developments establish the control at the point where it can be most effectivelyapplied, i.e., on the apparatus that must cross the intersection.

Many students of the problem of traffic control and its relation to fire department response, believe this on-the-spot control, perhaps coupled with the use of fire lanes, may provide the answer to these vexing problems.

Naturally, whatever system is adopted, education of the motoring and pedestrian public is a requisite. Obviouslythis will take time. However, with public spirited commercial vehicle operators, truckers and taxicab operators as key users of the streets, once convinced on the advantages of these improvements, they maywell, in turn, serve as bellwethers for the motoring public.

There are of course, other details to be ironed out such as installation, upkeep and maintenance and the like. Another factor is cost. In view of the fact that the installations require practically no additional poles, pedestals or wiring, no digging of trenches and/or laying of conduit, and that supervision of the system is possible at all times, cost may not be as serious a factor as the progenitors of tire systems at first feared. And as for maintenance, it is reported that this should be no more serious or costly than upkeep of the other forms of wired and wireless traffic controls. Time, of course, will tell the tale.

Already the initial installations are receiving acclaim, with due reservations for the brief period of experimentation which some of them have had.

In Maywood, III., the radio control installation reportedly has been in operation at a number of intersections for a number of months. This is said to be the first installation of its kind, and it has been demonstrated to officials of many municipalities.

In New Haven, Conn., Fire Chief Thomas Collins reporting to FIRE ENGINEERING, says that in his city the police department installs the receivers and the fire department places the transmitters. Questions not definitely settled are the exact distance that lights will operate with the apparatus, and some details of directional control.

Another city which has been experimenting with an electronic traffic control system is White Plains, N. Y. Fire Chief Edward MacDonald and Superintendent of Fire Communications Thomas Divine report their installation still in the experimental stage. In both this city and others, engineers of the manufacturers are cooperating with the fire communications personnel and police linemen on matters of installation and maintenance.

These and other progressive fire officials who see the possibilities in the driver-control of traffic signals are tackling the problem in the same spirit that has brought drastic improvements in the field of fire fighting. Chief Thomas Collins voices the sentiments of the cautious majority when he says, “I believe in all fairness, that the system should be given a year’s field test before voicing any approval or disapproval of the installation.”

As for the fire lane innovation, New York City fire officials, including Fire Commissioner Edward F. Cavanagh, Jr.; Fire Chief Edward Connors and Deputy Chief Thomas O’Brien, who heads the group at work on this project, all of whom have watched the pilot tryouts, are enthusiastic about it. More, much more, is destined to be heard about this development as the days pass.

Acknowledgment: The editors acknowledge the assistance of the following in the preparation of this report: The New Haven, Conn., Fire Department, Chief Thomas Collins; the New York Fire Department, Commissioner Edward F. Cavanagh, Jr., Chief Edward Connors and staff; the White Plains, N. Y., Fire Department, Chief Edward MacDonald; the Maywood, Ill., Fire Department, Chief Dave Smith (report to FIRE ENGINEERING, March, 1955); the Columbia, S. C., Fire Department, Chief A. Me. Marsh; and the following manufacturers: Eagle Signal Corp., Moline, Ill., Electronics Protection, Inc., Melrose Park, Ill. and the General Electric Company.

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