US1917165A

US1917165A - Traffic signal system

Info

Publication number: US1917165A
Application number: US450607A
Authority: US
Inventors: Marion B Thompson
Original assignee: Individual
Current assignee: Individual
Priority date: 1930-05-08
Filing date: 1930-05-08
Publication date: 1933-07-04
Anticipated expiration: 1950-07-04

Description

July 4, 1933. M. B. THOMPSON 1,917,165

TRAFFIC SIGNAL SYSTEM Filed May 8, 1930 G OneWa Y Srreei' I I Mi.

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ATTORNEY Patented July 4,, 193

STATES JUN B. THOMPSON, CF LOUISVILLE, KENTUCKY TRAFFIC SIGNAL SYST Application filed May 8 1930. Serial No. 450,607.

This invention relates to trafic signal systems for regulating vehicular trafic at street intersections. At the present time street intersection traffic signal regulations vary quite widely in the difierent communities and quite often the regulations in the congested areas of any particular community differ from those employed in the other areas ofthe same community. Particularly isthis true in conim nection with the permissible turns at the The regulations various street intersections. in this respect difier more widely'than in any other phase of trafic control with the result that a person traveling from one community to another is often at a loss to know how to proceed.

The three light, three color-green, yellow and redtraiiic signal has been adopted by practically all communities using signal lights and has come to be considered as the standard signal. With this type, the generally accepted or standard regulations are that the green or go light is a signal permitting movement in any direction except as modified by the turn regulations, the red or stop light is a signal prohibiting movement in any direction except as modified by the turn regulations while the yellow or caution light is a si 'al of the approaching change of lights. 11 some communities additional lights are employed to inform the traveler as to the permissible or non-permissible turns as the case may be. Naturally additional lights require additional control apparatus, larger signal supports and are otherwise considerably more expensive than the standard three light signal alone. A "less expensive arrangement utilized by other communities to inform travelers of permissible turns consists" in the use of printed signs in connection with the standard three light signal. The use of printed signs, however, is ob jectionable inasmuch as they must be laced out of the line of vision from the tra c flow to the signals where they are very apt to be overlooked. Consequently they are not highly eflicient in the prevention of accidents or traflic regulation violations. They are also objectionable because of their unsightliness which is accentuated by the conspicuous position in which they must be placed to accomplish their purpose even inefficiently. Furthermore such signs must be printed in big bold type in order to be readable thereby necessitating comparatively large signs atcorners having more than one turn regulation such, for example, as corners where left turns are not permitted on the go signal and right turns are permitted on the stop signal. Ubviously an increase in the size of the signs further accentuates their unsightliness and, at the same time, requires heavier and more expensive supports than otherwise in order to meet the increase in Weight and Wind resistance.

The principal object of the present invention is to provide a traflic signal system, uti-- lizing the standard three light signal, which will fully inform travelers of the permissible or non-permissible turns at each specially regulated intersection, and, which will accomplish this object without the use of print-.' ed signs, additional lights or other similarly objectionable or expensive equipment.

A further object is to provide a traflic signal system of the character stated in which the standard three light signal units of existing systems may be utilized without requiring any change in the position, location, or operation of the various units comprising the system and without entailing any material expenditure of time or money.

Generally stated, the invention consists in arranging in the line of vision from the traflic flow to the non-standard turn-regulated stop and/or gosignals of a standard three light signal, a direction indicating symbol to indicate positively the permissible turn and thereby negatively show the non-permissible turn. By placing the direction indicating symbol in the line of vision as stated, a traveler approaching a non-standard turn-regulated intersection and looking at the turn-regulated signal must, of necessity, see the indicator. Consequently he is instantly informed of the 95 turn regulation and thus not required to hesitate and search for printed signs or other sources of information. It should be understood that the. direction indicating symbols need only be used in connection with signal 1 units located at street intersections having one or more non-standard turn regulations. Naturally at the intersections having the generally accepted or standard regulations, the traveler knows instantly, upon seeing the green signal, that he is permitted to make either turn, and, upon seeing the red signal,

manner in the line of vision between the flow Jae of traffic and the particular signal to which it may apply. Preferably the indicator is made of triangular form as shown at 1 in Figure 1 and is applied directly to the lens 2 of the signal light as by painting it thereon or pasting a suitable triangular form thereto. The lens 2 is positioned at the proper signal light of its particular signal unit in a manner such that the apex 3 of the symbol points in the direction of the permissible turn.

The. diagrammatic layout shown in Figure 2 illustrates the application of the invention to a standard three light traffic signal system. In this case a series of vehicles 4, '5, 6, and 7 are shown as traveling along the same street in the direction of the arrow A, each vehicle being about to cross a different intersection. Each of the intersections is controlled by a different three light signal unit, the go or green, caution or yellow, and stop or red,

signals of each unit being indicated respectively by the letters G, Y and lit.

The first intersection that is to say the one which vehicle 4' is about to cross, is shown as a standardly regulated intersection. The driver of this vehicle, upon looking at the signals, will immediately know: if the signal be green, that he may go straight ahead or make either turn; and, if it be red, that he is not permitted to move in any direction.

The driver of the next vehicle (5) by looking at the signal, will see the direction indicator 1 on green only, and, since it points to the left, he will immediately know: if the signal be green, that he may go straight ahead or turn to the left only; and, if it be red, that he is not permitted to move in any direction. Thus this driver, simply by looking at the signal, a required act in any signal system, is instantly and fully informed of the non-standard regulations controlling the flow of traffic at this intersection. The signal thus operates to prevent the driver from making a wrong turn whether or not he is aware of the fact that the cross street is a one way street permitting travel to the left only. Furthermore it will tend to make him aware of the fact that the cross street is a one way street without requiring the use of signs to point out such fact.

At the next intersection, the cross street is shown as another one way street permitting travel to the right only. In this case the driver of the vehicle 6 by looking at the signal, will see direction indicators 1 pointing to the right on both red and green, and consequently he will immediately know: ifthe signal be green, that he may go straight ahead or make a right turn only; and, if the signal be red, that he is permitted to make a right turn. The advantages of the indicator with respect to the one way phase of the intersection, are again apparent.

By looking at the signal of the last intersection, the driver of the vehicle 7 will see a direction indicator 1 pointing to the right on red only, and consequently he will immediatelyknow: if the signal be green, that he may go straight ahead or make either turn; and, if the signal be red, that he is permitted to make a right turn.

The foregoin is, of course, merely illustrative of the apphcation of the invention and is made to bring out the advantages of the inventi on and is not to be construed as a limitation thereon. It is apparent from this illustration that the invention may be easily, quickly and inexpensively applied to existing systems utilizing standard three light signal units and that it eliminates the use of both unsightly signs and expensive additional light equipment. It has further advantages in that it is easily understood and does not obscure the signal lights although positioned directly in the line of vision.

Having described my invention, I claim:

1. In combination, a traffic light signal unit of the standard type having diiferently colored signals for the standard regulation of traffic, and means permanently associated with one of said signals modifying the light emission therefrom for indicating the only turn permissible on that signal.

2. In combination, a traffic light unit of the standard type having different colored signals for the routine regulation of traffic, and means permanently associated with one of said signals modifying the light emission therefrom for indicating a special turnregulation applying to that signal.

In testimony whereof I hereunto affix my signature this 6th day of May, 1930.

MARION l3. THOMPSON.