by Eric Reiss - 17 January 2004

 

2004 marked the 50th anniversary of the red stop sign

Web folk and usability types love to talk about the ubiquitous stop sign. It's a great icon. It transcends borders and cultures. Everybody understands it. And this year, it celebrates its 50th birthday!

Along with the Coca-Cola logo, the stop sign is one of the most widely recognized symbols in the world. (Is it just a coincidence they're both red and white?) Anyway, I thought it might be interesting to find out exactly who was responsible for its creation.

Close but no cigar
Around 1890, William P. Eno of Saugatuck, CT published an article in Rider and Driver, in which he proposed a set of traffic regulations, including stop signs. Many of his suggestions were taken up by the New York City police and other municipalities soon followed. Not surprisingly, his book on traffic safety became a best-seller when the automobile made its debut (the first recorded car accident was in Ohio in 1895). However, there is no indication that anyone actually made a stop sign. Until... 

Detroit, MI installed the first recorded stop sign in the summer of 1915 - black letters on a white background, painted on a piece of sheet metal. And five years later, they installed the world's first three-color electric signals. (See notes at end of this article). Leave it to the pros from Michigan to enlighten us.

 

Meet the creative team
The first serious work started in late 1922 when John T. Donaghey (Wisconsin's State Highway Engineer), Walter F. Rosenwald (Minnesota's Maintenance Engineer), and A.H. Hinkle (Indiana's Superintendent of Maintenance) took a road trip to find ways to standardize highway signage. Railroad-highway crossings, one of the greatest dangers back then, inspired the most creativity, often featuring a skull-and-crossbones - which explains the crossed signs we still have today.

The shape of things to come
The three men decided to assign special meaning to the shape rather than the words. According to Rosenwald, 'The underlying thought was that, if each shape had a definite meaning, it would be a great advantage for night driving as undoubtedly the shape could be distinguished long before the words could be.' An official report was made to the Mississippi Valley Association of State Highway Departments (MVASHD) in Chicago in January 1923. The association adopted the following standards:

- Round: warnings at railroad crossings.
- Octagonal: STOP
- Diamond shaped: 'slow' warnings
- Square: caution or 'attention' messages
- Rectangular: directional and regulatory information

The signs were to be black-and-white. Because round and octagon shapes required the most cutting (and wasted the most material), they were chosen for the fewest installations. Stop signs were standardized at 24? x 24? since this was the maximum size that could be produced in the sign-making presses of the day. 

 

A second standardization group
In 1924, another group, The National Conference on Street and Highway Safety began to address similar issues, suggesting 18"x18" stop signs with red letters on a yellow background.

Naturally, two groups working on the same project was bound to cause trouble. So, in 1932, the two formed the Joint Committee on Uniform Traffic Control Devices and in 1935 they published the first 'Manual on Uniform Traffic Control Devices for Streets and Highways' MUTCD for those in the know. Since then, nine revised and updated editions of the manual have been published. The first edition in 1935 defines a "stop" sign as a 24"x24" octagon with red or black letters on a yellow background.

 

1954 - a watershed year
In 1954, the MUTCD made a major change - the background color was changed to red and the lettering was made white. This, then is the stop sign as we know it today.

The current regulations state:
'The current minimum requirements for stop signs are 30"x 30" octagon with white lettering and border on a red background. The sign shall be mounted so to be visible for a minimum distance determined by the 85th percentile approach speed; at a minimum height of 5 or 7 feet and offset from the traveled way a distance appropriate for the specific location. Larger sign sizes and different offsets are a part of the engineering study and design process that is required prior to installation. The MUTCD does not require installation of stop signs. It provides warrants which are minimum condition to consider installation.'

For more info, see:

http://www.fhwa.dot.gov/infrastructure/numbers.htm

http://signalfan.freeservers.com/road%20signs/stopsign.htm

http://mutcd.fhwa.dot.gov/kno-history.htm

P.S. Traffic lights come before stop signs
It seems the world's first traffic signal was a red/green lantern mounted on a 22 foot pole outside Britain's Houses of Parliament. Invented by J.P. Knight and installed on December 10, 1868, it was operated by a policeman who rotated the lantern at regular intervals. Three weeks later, on January 2, 1869, the gas-fueled lamp exploded, killing the policeman, and in 1872, the tempermental device was removed entirely.

Apparently, the Brits gave up at this point and development moved across the Atlantic.

On August 5 1914, Cleveland, OH became the first U.S. city with an electrically powered traffic signal. It had red and green lights, plus a warning buzzer that sounded just before the light changed. The inventor, Garrett Morgan, was awarded a patent in 1923.

In 1920, Detroit policeman William Potts used red, yellow, and green railroad lights and about thirty-seven dollars worth of wire and electrical controls to make Detroit's first traffic light - the first three-color light ever produced. Installed on the corner of Woodward and Michigan Avenues, within a year, the city had 15 of the new, automatic signals.

Origins of red and green
Evidence suggests the signal colors were borrowed from the railroads, where red meant 'stop', green meant 'caution', and clear (white) meant 'go'. These came into use in the 1830s and 40s. Around 1914, a broken red lens caused a locomotive engineer to mistake this for a clear 'go' and smash into an oncoming train with disasterous results (another example of Deadly Design). Subsequently, the red/yellow/green signals we use today were adopted; yellow was thought to provide the greatest contrast to the other two colors.

Old-time railroaders insist that the use of red comes from farmers using red shirts to flag down trains. It's a nice story, but probably not true. Red has been a symbol of danger since the time of the Greeks. The reasons for the use of green have been lost to history.

Comments or questions?

October 21, 2004 - James Johnson of St. Louis informs me that Garrett Morgan, who was awarded a patent for an electrically powered traffic signal was an African-American. He feels I have done all African-Americans an injustice by not mentioning this fact.

I sincerely apologize to anyone who feels slighted. Quite frankly, I didn't think this was a racial issue, so I didn't mention Mr. Morgan's ethnic background.

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