Lessons from the Highway Style Guide

The Federal Highway Administration’s (FHWA) style guide is almost 900 pages long.

The guide details all the rules and nuances of traffic safety signs and roadway markings on U.S. roads. It covers everything from font specifics to background colors, location, and marking orientation.

It has been around since 1935 and goes into incredible detail on sign specifics.

The website Beautiful Public Data breaks down some of that detail and its impact. For example, here’s a part of the guide’s entry on street name signs:

“On multi-lane streets with speed limits greater than 40 mph, the lettering on post-mounted Street Name signs should be composed of initial upper-case letters at least 8 inches in height and lower-case letters at least 6 inches in height.”

On the road, of course, these details can literally be a matter of life and death. And the guide has important takeaways for any brand seeking to create consistency across its materials and put a set of rules in place.

The Rules of the Road

Most significantly, the guidance falls into three distinct categories. Mandatory rules are denoted as “standard” and always use the word “shall” when describing how they’re to be implemented. Other rules are “guidance” that “should” be followed. Then, there are “options” that “may” be followed.

These distinctions are crucial and a best practice for any style guide. Design is an inherently creative endeavor, and new communications channels and formats pop up all the time. Clearly defining which rules can be tweaked and which are set in stone can help avoid confusion and complications down the line.

The guide also tackles potential inconsistencies across states, which act as quasi sub brands for the agency. States must comply with the rules or submit their own approved addendums or guides that are in “substantial conformance” with the national rules.

Finally, the guide underscores the potential for unintended consequences of deviating from established style guide rules. In 2003, there was a push to replace the longstanding “Highway Gothic” font with “Clearview,” designed to improve readability at night.

However, the font had to be made larger on road signs, which sometimes required larger signs, all of which cost more money. States weren’t sure which font they were supposed to use, creating additional confusion. Ultimately, FHWA reverted to the original font and even had to submit a Congressional report detailing the issue.