Stop signs have been a crucial part of road infrastructure and traffic regulations for decades. While the basic purpose of stop signs has remained the same over the years – to instruct drivers to come to a complete stop before proceeding through an intersection – the appearance and specifications of stop signs have evolved since they first came into widespread use in the early 20th century.
The origins of stop signs
Stop signs first began to appear in the late 19th and early 20th centuries as motor vehicles became more popular on roads that were originally built for horses and carriages. As cars and trucks began sharing the roads with pedestrians and horse-drawn buggies, new traffic regulations were needed to reduce accidents at busy intersections.
The first known stop sign was placed in Detroit, Michigan in 1915. It was a white square sign with black letters reading “Stop”. These early stop signs were put up at the discretion of local authorities and varied in shape, size and color. It wasn’t until the 1920s that efforts were made to standardize the design and use of stop signs across the country.
Stop sign design in the early 20th century
In 1923, the American Association of State Highway Officials (AASHO), now known as the American Association of State Highway and Transportation Officials (AASHTO), issued guidelines for a standardized stop sign. The new regulations specified:
- A hexagonal shape
- White background
- Black uppercase lettering reading “STOP”
- A height of 24 to 30 inches
- Reflectorized material for visibility at night
By 1954, with the establishment of the Manual on Uniform Traffic Control Devices (MUTCD), the hexagonal shape, color scheme, size and mounting height of stop signs were further standardized by the federal government.
Stop sign specifications in 1950
So what exactly did stop signs look like in 1950? Stop signs had taken on their distinctive red, hexagonal look during the previous decades, so the stop signs motorists came across in 1950 would have appeared much the same as the stop signs we see today.
Here are the key specifications for stop signs in 1950:
- Shape: Hexagonal
- Dimensions: 30 inches wide
- Material: Aluminum sheet metal; enameled steel
- Color: Red background; white lettering
- Lettering: 8-inch uppercase white letters reading “STOP”
- Mounting Height: 5 to 8 feet above the roadway
- Retroreflectivity: Built with reflective white borders and letters for visibility at night
The 30-inch width allowed stop signs to be easily visible to motorists. Constructed of durable enameled steel or aluminum, they could withstand the elements and last for years posting at intersections across the country.
Evolution of stop sign design
While the basic familiar red hexagon stop sign design was standardized by the 1950s, some refinements have been made over subsequent decades:
- 1971: The MUTCD adopted national standards for retroreflective sign materials.
- 1971: Stop bars (solid white lines on the roadway indicating the stop point) became widespread.
- 1975: Minimum mounting height raised to 7 feet for visibility.
- 1980s: Transition from steel to aluminum construction.
- 2000s: Introduction of high intensity prismatic retroreflective sheeting.
Today, with these minor enhancements, stop signs remain a crucial traffic control device regulating right-of-way and keeping intersections safe in the 21st century.
Interesting facts about stop signs in the 1950s
- It wasn’t until 1954 that stop signs were required to use the distinctive red color.
- In the 1950s stop signs started to transition from steel to aluminum construction.
- The original stop signs with black lettering instead of white were still in use in some areas during the 1950s.
- Stop signs were mounted between 5 and 8 feet high, lower than today’s regulated mounting height.
- Many early stop signs were made by prisoners as part of correctional industries programs.
Stop sign usage in 1950
By 1950 stop signs were widely used across the United States. Here are some statistics on stop sign usage in the early 1950s:
- It’s estimated there were close to 2 million stop signs in use by 1955.
- Approximately 75% of intersections had stop signs regulating traffic flows.
- Areas with high volumes of automobile traffic made greater use of stop signs than rural areas.
- 2-way and 4-way stop intersections were both common.
- Stop sign installation was the responsibility of state and local jurisdictions.
As the Interstate Highway System expanded during the 1950s, stop signs became even more prevalent at highway access points across rural and urban America.
Stop sign materials in 1950
In the early 20th century, stop signs were made from various materials including tin and wood before durable enameled steel became standard. By 1950, stop signs used:
- Enameled steel: Durable 14-gauge steel with a baked enamel coat resistant to rust and wear.
- Aluminum: Lightweight aluminum sheet metal was also used as it became more available after WWII.
- Reflective coatings: Signs had reflective white lettering visible at night.
Enameled steel was common but shifts to lightweight, corrosion-resistant aluminum became more prevalent into the 1960s. These materials ensured stop signs could endure harsh weather and traffic conditions.
Stop sign legibility and visibility
For stop signs to serve their traffic control function, they must be clearly visible and legible for motorists approaching an intersection. In 1950, the standards included:
- White uppercase letters on a red background.
- 8-inch lettering designed to be readable from a distance.
- Reflective coatings for nighttime visibility.
- Mounting height of 5-8 feet above the roadway.
These specifications made stop signs highly visible both day and night. The distinctive shape, colors and large lettering allowed motorists to quickly recognize and comprehend the stop instruction.
Historical photos of stop signs
Looking at photos of stop signs from the early to mid 20th century provides visual examples of what stop signs looked like and how they evolved over time:
- 1915 – A square white sign reading “Stop” in black letters in Detroit, one of the earliest known stop signs.
- 1923 – Black and white stop sign images show early standardized hexagonal designs.
- 1940s – Full red background stop signs begin to appear around major cities.
- 1950s – Distinctive red hexagonal stop signs proliferate across America’s roads.
It’s fascinating to see how the familiar stop sign design took shape over decades of changing transportation needs, regulations and technologies.
Variations in early stop sign designs
While standardization efforts began in the 1920s, some variation in stop signs could still be found in different regions into the 1940s and 1950s, including:
- Black or yellow lettering instead of white
- Different sizes and shapes beyond the hexagon
- Hand-painted signs with non-standard fonts and spacing
- White borders instead of reflective outer coating
But by 1950, the iconic octagonal red stop sign had become the clear standard across the country as regulations came into alignment.
Conclusion
Stop signs have a fascinating history paralleling the rise of the automobile in America. While the basic purpose has stayed the same, the red hexagonal stop sign that originated in the early 1900s underwent standardization and improvement over several decades to become the ubiquitous traffic symbol we know today. By 1950 the stop signs motorists drove past each day were likely quite similar in appearance, construction and use to those currently regulating traffic flows at intersections across the nation.
| Decade | Stop Sign Design and Specs |
|---|---|
| 1900s-1920s | No standard design; varied shapes, sizes and colors |
| 1923 | AASHO recommends standard hexagonal shape, white background, black letters |
| 1930s-1940s | Reflectorization introduced; red background becomes standard |
| 1950s | MUTCD aligns specs; red hexagon, white letters, reflective coating |
| 1960s-1970s | Higher mounting heights; transition to aluminum |
| 1980s-Today | Prismatic reflective materials; high visibility stop bars |
This table summarizes the evolution of stop sign design and specifications over the decades. In the 1950s the familiar red hexagonal stop sign was standardized, but refinements continued in subsequent years to improve visibility and durability.
