The Lighter Side of Publishing

Highway Hieroglyphics

While everyone in the publishing industry knows that fonts, graphics, and colors are important, did you know that traffic engineers are just as interested in design for the highway signs that guide us along the roads? Since Memorial Day signals the start of the summer driving season, now’s a good time to take a look at the design behind highway signs.

Road signs have been around since Roman engineers erected stone markers indicating distances and directions along the roads they built. In colonial America, markers gave the distance to the next town or provided directions at crossroads.

Less than a decade after Henry Ford’s first Model T rolled off the assembly line, signs began to proliferate along roadways, put up by auto clubs and state highway departments. There was no consistency in the style of early signs, and the lettering was hand-painted and all uppercase because it was easier to make capital letters. But by 1930, the Federal Highway Administration (FHA) had developed the first official Manual on Uniform Traffic Control Devices—and they are still updating it today (http://mutcd.fhwa.dot.gov).

The manual lays out rules about the shapes to use for certain kinds of signs. For example, the more sides a sign has, the more critical its message:

	Circular signs (with an infinite number of sides) are used for railroad warnings.
	Eight-sided signs are only used for stop signs.
	Five-sided signs mark school crossings.
	Four-sided signs are informational rather than warnings or alerts.

And color matters, too:

Red signs signify strong warnings, including Stop, Yield, Do Not Enter, and Wrong Way.
Orange signs are used to caution drivers with temporary traffic control directions.
Yellow signs issue warnings and notice of curves, crosswalks, and other hazards.
Green signs provide mileage and directional information. (Looks like this sign needed another proof pass!)
Blue signs are for services and emergency assistance for travelers.
Brown signs designate points of interest and recreational areas.
White signs are used for regulatory signs, such as speed limits. (I’m sorry, officer—my in-dash calculator is broken…)
Light blue and purple signs are “reserved for future use” by the FHA.	?

The font for highway signs needs to be easy to read from a distance and at highway speeds. Since the first standards were created, highway signs have used a sans serif type called Highway Gothic. In 1949, a California state highway engineer named Ted Forbes made a bold move by modifying Series E Highway Gothic to include lowercase letters. Series E (modified) is the font still used for most highway signs today, but it’s on its way out.

In the early 1990s, engineers began to study the font’s legibility. The research led to the design of a new font that is easier to read called Clearview (at bottom). Twenty states are currently using the new font when they replace signs. Right now, you can see new signs in Clearview along I-80 in Pennsylvania, but it will probably be decades before the entire country undergoes a complete highway sign makeover.

Change comes slowly, and some things don’t change at all. For instance, the structure used to hold directional signs is called a gantry and was originally designed to hang signals above tracks when railroads were the main form of transportation. On highways, the placement of a sign on its gantry gives you some clues about what to expect. Usually, a directional sign, such as an Exit Only sign, is hung above the proper lane so that you can move to that lane. The location of the exit number panel at the top of a sign will tell you whether the exit goes left or right.

In most states, the exit numbers also help drivers orient themselves because the numbers correspond to mile markers within the state—that is, Exit 22 is approximately 22 miles from the border where the interstate crosses into that state. Mile markers usually begin at 0 on the west or south border and go up as the road heads east or north.

Electronic signs are the newest innovation in freeway information systems. Permanent electronic signs provide traffic alerts, and temporary signs are often used to warn motorists about highway construction. Because the wording of these signs can be changed easily, you never know what you might see—look for important messages while you are decoding the other signs along the highway this summer!