SEO STRUCTURE
1. Introduction
The purpose of any road sign is to convey specific information, but exactly how it’s presented has changed over the years. Wind the clock back two decades or so and you’ll find that the Manual on Uniform Traffic Control Devices (MUTCD) stated that all standard highway signs should be in capital letters. Yet, when the latest edition of this government-issued manual released in 2023, it stated that conventional green and blue road signs should use a mix of uppercase and lowercase letters.
Speaking to WLRN, Gene Hawkins, Professor Emeritus of Civil & Environmental Engineering at Texas A&M University, explained the reason for the change. He said that it was the result of additional research on how drivers perceive signs while on the road, especially when they need to see signs from far away. This research suggested that drivers find it easier to read signs when they can “recognize the shape of a word,” and using mixed-case lettering formed “patterns” to make words more legible.
These patterns are standardized, with the MUTCD dictating how both uppercase and lowercase letters on a sign should look. As well as stating a minimum uppercase letter size for each type of sign, the manual also says that, on a standard sign, the “nominal loop height” of the lowercase letters should be ¾ the height of the uppercase letter. Nominal loop height refers to the main body of the letter, excluding any stems or tails such as the ones you’ll find in the letters “d” and “q.”
There are some exceptions to the new rules.
Kristi Blokhin/Shutterstock
The mixed-case lettering has been proven to help drivers understand signs from a greater distance away, but there are some instances where the traditional all-caps lettering is still required. According to the latest edition of the MUTCD manual, “cardinal directions, action messages, and special characters” are still required to be entirely uppercase. Cardinal directions include “NORTH” and “SOUTH”, while action messages include
Key Points
– The purpose of road signs is to convey specific information.
– The new rules change how signs are presented, with mixed-case lettering being standard.
– The MUTCD mandates a minimum uppercase letter size for each type of sign.
– The “nominal loop height” of lowercase letters should be ¾ the height of uppercase letters.
– The “cardinal directions” include “NORTH” and “SOUTH” for cardinal directions, while action messages include “NORTH” and “SOUTH” for action messages.
These points highlight the importance of understanding the nuances of road signs and how they can be effectively communicated to drivers.
