Early Speed Limit Signs in the United States From the 1920s

As cars have become faster, speed limit signs have naturally kept up. The first speed limit signs were posted at city and town limits. Early signs were not reflective. By the middle to late 1920s however, many cities required that speed limit signs be illuminated. The early requirement was for a famous GE style of light, called a “MAZDA” lamp. The New York State legislature, in 1925, passed a law that “each city shall have placed conspicuously [signs on] each main highway, where the rate of speed changes [and signs shall be] adequately illuminated between sunset and sunrise.”

For many townships and cities, however, internal illumination proved difficult. Too many roads needed speed limit signs and power was not readily available. As a result, speed limit signs started to use “cats eye” reflectors. Signs with reflectors captured the light from early auto headlights and reflected the message back to the driver.

By the late 1920s however, the interstate system adopted signs which initiated many of the design elements that we see today on our current Speed Limit sign designs. The signs were rectangular, taller than wide, printed in black and white and highlighted the actual numerical speed limit in taller letters. Rectangular signs “are used to carry direction of use or benefit to the driver” (1927 AASHO). AASHO also cited that the dimensions of Speed Limit signs (a tall rectangle) distinguish them from other directional signs.

But, most early roads were not part of the nascent interstate system, nor were they part of a city’s street network. These early roads, which still transverse rural communities, seldom posted signs. For many, the “honor system” was predominant.

The debate between those demanding the freedom to travel at high speeds in an unregulated environment and others citing the need for greater security and increased regulation (e.g. signs) was common in the 1920s and 1930s. For certain communities, “too slow speeds” were also an issue. As reported in the June, 1925 Lyle Sign Post, the chairman of the Maryland State Roads Commission, John Mackall, “advises substitution of the maximum speed limit with a minimum speed limit, to speed up traffic. Mackall also suggested slow-moving vehicles be barred from main streets during peak hours.”

Many states did not require drivers licenses. As part of the author’s own family lore, there is a wonderful story of two strong-willed daughters, Lydia and Mary, traveling from their home in North Dakota to visit their father, Senator Langer, in Washington, DC. With little experience, other than on farm machinery and certainly no license, they ended up in Washington in record time. Speed limits (and the few Speed Limit Signs) were proudly ignored.

For more discussion, see the excerpt below on fixed speed limits: “Should there be Fixed Speed Limits?”. Even in the 1930s and 1940s, speed limits were not uniform. Should speed limits change, depending upon the weather conditions, road conditions and time of day (for example, during school hours)?

It was not uncommon to find that speed limit regulations changed from jurisdiction to jurisdiction. Towns often found themselves at odds with neighboring communities. Moreover enforcement was also inconsistent. See the 1927 excerpt below from one Mayor’s reported leniency towards speeders. In spite of this speed limit variability, school zones and pedestrian areas have always been more tightly regulated.

(via Road Traffic Signs)