License-Plate Standard Proposed

The Journal of the Society of Automotive Engineers
March 1925

R.M. Hudson Believes Standard Should be Adopted by State Authorities

In an extensive survey of the possibilities and desirabilities of standardizing license-plates. R.M. Hudson, chief of the division of simplified practice of the Department of Commerce, recommends that a National standard for automobile license-plates should be adopted by the state authorities.

The present SAE Standard for License-Plate Bracket-Slots specifies two 9/32-in. slots 3 in. long placed so as to allow for mounting plates with the bolt-holes from 4 � to 10 � in. apart. This standard will be included in the March issue of data sheets.

The following abstract of the survey issued by the Division of Simplified Practice gives the more important and interesting features outlined:

The license plate serves two major purposes, registration and identification. The purpose of this article is to show that both of these purposes can be adequately served with standardized plates, standard in all features except color, name of issuing state and year issued. Plate, letter, and numeral sizes, gage of metal, punching, mounting brackets, location and degree of illumination at night can all be standardized with benefit to state and municipal authorities, plate makers, car builders, accessory manufacturers, motorists and even to pedestrians.

To illustrate the possibilities in this direction, each feature to which standardization may be applied will be discussed.

Standard Plate Punching and Mounting
When SAE first attempted the standardization of license-plate punching, it found difficulty in having its recommended standard adopted by the state motor-vehicle authorities. The only practical alternative, therefore, was to specify mounting bracket slots of sufficient length and width to accommodate as many different state plates or tags as possible within a reasonable degree of variation in punching. The bracket slots proposed by SAE are each 3 in. long and 9/32 in. wide and it is known they will accommodate without difficulty the plates of 46 of the 48 states, Louisiana and Mississippi plates not having been checked.

Standardization of plate punchings would permit the revision of the recommended mounting-bracket standards to specify either shorter slots or only holes. This in turn would accelerate the adoption and installation of standard mounting-brackets by car builders as standard equipment on their cars, and help the accessory manufacturers in producing standard tail-lamps.

At the suggestion of SAE, the division of simplified practice of the Department of Commerce took up the matter with the motor-vehicle authorities in each state. The division pointed out that through uniformity in the punching of the plates and the slots or holes in the brackets, the plates of any state would fit the brackets on any car. This would not only be a convenience to the car builders, but also to the automobile dealers and the motoring public. It would facilitate or accelerate the establishment of a standard method of display, including not only a standard location on the car, but also a relatively standard degree of visibility at all times. Replies from over two-thirds of the states favored standardizing the punchings. None of them opposed the idea. Though state laws define other tag features with great exactitude, there are no state laws governing the punchings of the plates. Because of this freedom of choice on the part of the state motor-vehicle authorities, it should be relatively easy to standardize on plate punchings which would permit SAE to reduce its present bracket slot lengths from 3 to 1 in., or even to � in.

From statements made by both the state authorities and the plate makers, it appears there is no good reason why standard plate punchings and standard mounting-bracket slots, or preferably holes, should not be adopted by all concerned. Such cooperative action would eliminate the mutilation or defacing of plates often resulting from the necessity of putting holes through the plate at points other than those originally provided.

Standard Size of Plate Symbols.—Variation in sizes of numerals, letters and other details is very pronounced. State laws differ widely on these dimensions. This variation cannot help but cause difficulty to those whose duty it is to watch licenses on passing cars. There is no doubt a normal minimum letter or digit size that might well be adopted as standard for all plates.

Not infrequently the spacing of the digits is too close, giving a blurred effect to the entire number. Again, the state initials or abbreviations, or the year of issue, encroach on the digits in the license number, thus adding to the confusion. What is the ideal or best minimum spacing or arrangement should also be determined. The arrangement of the abbreviation of the state name is another possible point of standardization. Some appear to the left, others to the right of the license number. Some are relatively large and others small. The location, and also the size, of the type in the abbreviation might well be standardized. Perhaps a better idea is to use the state name spelled out. The 1925 Arizona tag carries the complete State name in fairly large letters and is an excellent example of what might be done in many other cases.

The standardization of the location, and also of the size of the numerals in the year of issue are also worthy of consideration. There seems to be no good reason why the arrangement of all the plate symbols cannot be standardized as to their respective locations.

Standard Gage.—The gage of metal used varies from No. 14 to No. 26. A stiff plate resists bending. The thinner the plate, the less durable it is likely to be. There is no doubt some consistent minimum for this feature. Similarly, sheets of certain grades or qualities resist rust and corrosion better than others. A selection might be made on the basis of a life of 1 year under normal conditions of use as being the lowest quality acceptable.

Standard Size.—In the replies mentioned, standardization of plate size is also suggested. Plates are now made from 8 to nearly 20 in. length and from 4 to 6 in. in overall width. The smaller the plate, regardless of the color used on it, the more easily it is obscured or its identity shrouded. There is no doubt a minimum size below which a plate should not be made lest ease of identification is destroyed. That minimum size may well be that which the normal eye can readily visualize at normal car-speed.

Standard Code of Numbering.—The variety of numbering codes is nearly as great as the number of license-issuing bodies. Here again is an opportunity for standardizing on a code which is readily understandable by the majority of those concerned. A code letter might well be used to designate a common geographical section, or “sector,” in all states. This principle is used in mapping battlefields and in many other instances.

With such a code, the necessity for unduly long numbers and long plates diminishes. To illustrate, with the 26 letters in the alphabet and numbers running from 1 to 9999, it is possible to care for 259,974 licenses. If numbers run up to 99,999, then nearly 2,600,000 licenses can be covered. The shorter the number, the easier it is to remember, and the “A-2675” or even “B-98,356” is relatively easier for many people to remember than “1-514-692.”

R.A. Brannigan of the National Automobile Chamber of Commerce has suggested that, instead of numbering plates with the usual numbers, the letters of the alphabet also be used. When the end of the series is reached, start in the next column with the same series, and so on. If all the numbers and letters were used, there would be 36 integers instead of the present 10, but it is not very practical to use the full series, because the letter I and the number 1, and the letter O and the number 0 are identical, and moreover, utilizing the full alphabet would mean that certain combinations would spell actual words, which would be objectionable. This objection is readily overcome by eliminating the 1 and the 0, and the vowels, leaving 29 integers or symbols with which to work.

This would mean that there would be 29 license plates with only one symbol; 841 with no more than two; 2439 with no more than three; 707,281 with no more than four; and 20,511,149 with no more than five.

Standard Location.—A recurrent suggestion in the letters to the Division of Simplified Practice is that a standard location, front and rear, should be adopted. Front plates are often obscured by bumpers; rear plates by tire carriers. Plates mounted on fenders are often smashed or bent by the fender crashes now so common in congested areas.

It is certain that standardizing the location of these identification marks would help all concerned with their observance. There would be no “hunting around” to find the tag. It would be plainly visible for a definite number of feet in daylight, and its illumination at night could be more definitely controlled or guaranteed. A standard license-plate location would enable car builders to make suitable provision accordingly.

Standard Illumination.—Assuming a plate of standard size, located in a standard position, and such standards adopted throughout the United States of America, the present great lack of uniformity in night illumination would be largely overcome. SAE and the Illuminating Engineering Society have adopted a tail-light illumination standard. This standard represents what is now legal in Massachusetts, and meets the approval of members of the Eastern Conference of Motor Vehicle Administrators.

Coordination of Color Selection.—A state selecting a color combination seeks to avoid conflict with neighboring States, also with its own "last year's tags," or the obsolete tags of its neighbor. There are only seven basic colors in the spectrum, though there are many shades or tints of each. All these basic colors, as well as black and white, are used in combinations of two, one for the number and the other for the background. The question here is that of the relative visibility of each combination. Perhaps through annual meetings of the officials of the several Conferences of Motor Vehicle Administrators a coordination of color selections would be possible which would recognize all these problems.

It is obvious that as the importance of the license number is accentuated or emphasized, it will have a definite effect on many would-be reckless drivers. When it becomes easier to get the number of the reckless driver and the possibility of error in reading his number is reduced by standard mounting, standard size and standard illumination, then many a chance-taker is going to drive more sanely.