Section 3: Guide Sign Lettering

Letter Style

Sign lettering for word messages on freeway guide signs is uppercase, with the exception of destinations (names of places, streets, and highways). All destinations on guide signs must be composed of lowercase letters with initial uppercase letters. Since the 1950s, the Highway Series alphabet has been used as the letter style for freeway guide signs. The Series E (Modified) alphabet is the letter style that is most commonly associated with freeway signs. In the late 1990s and early 2000s, TxDOT began researching the performance of a different alphabet for freeway guide signs. This alphabet (or font) is known as Clearview, and it is available in several different stroke widths. In 2003, TxDOT decided to implement Clearview as the standard font for all freeway guide signs (white on green, white on blue, and white on brown). All of the guide signs illustrated in this handbook use Clearview for the white part of the sign legend.

Clearview is available in several different stroke widths. Clearview 5WR is used for the white legend in Exit Direction and Advance Guide signs. Other styles of Clearview are used in other types of white on green signs. Figure 4‑9 illustrates the letters and numbers for Clearview 5WR.

Several unique features to the Clearview font make it different from the traditional highway alphabet:

The loop height (or x-height) of the lowercase letters is greater than the 75 percent associated with the highway alphabet.

The letter height is not independently specified for lowercase letters.

The lowercase ascender letters (b, d, f, h, k, l, and t) are taller than an uppercase letter of the same height.

The fractions are taller than an uppercase letter of the same height.

Clearview 5WR font for white legend onfreeway guide signs. (click in image to see full-size image)

Figure 4-9. Clearview 5WR font for white legend on freeway guide signs.

Letter Size

The Texas MUTCD provides guidance as to the letter height on guide signs. For freeway guide signs, the message dimensions and letter size must be determined first, and the outside dimensions second. Lettering size on freeway signs is dependent on the type of interchange or sign, and must be the same for both rural and urban conditions.

Letter and numeral sizes for freeway guide signs according to interchange classification and component of sign legend are given in the Texas MUTCD. The minimum and desirable sizes for sign elements on Advance Guide and Exit Direction signs are shown in the following table. The minimum sizes for sign elements on other types of freeway signs are provided in Chapter 3.

Minimum Letter and Number Sizes for Advance Guide and Exit Direction Signs
Type of Sign and Sign Elements		Minimum Height (inches)	Letter Style
Exit Panel
	Word	10	CV 4W
	Numeral and Letter	15	CV 4W
Interstate Route Sign
	Numeral¹	18	D
	Shield (1-2 Digit)	36 × 36	—
	Shield (3 Digit)	45 × 36	—
U.S. or State Route Sign, Business, Loop, or Spur Interstate Route Sign
	Numeral¹	18	D
	Shield (1-2 Digit)	36 × 36	—
	Shield (3 Digit)	45 × 36	—
Or Alternative (Ex: U.S. 56)
	Initials	12	CV 5WR
	Numerals	15	CV 5WR
Cardinal Direction
	Word²	12	CV 5WR
“BUSINESS”
	Word	10	CV 5WR
Name of Place, Street, or Highway
	Word	16	CV 5WR
Distance Message
	Numeral	15	CV 5WR
	Fraction	10	CV 5WR
	Word	10	CV 5WR
NOTES: 1. In a few cases numerals cannot be accommodated within the space available. For these cases, the standard series D numeral may be reduced to C, or as a second choice to the next smaller height commonly available. 2. It is Texas practice that the entire cardinal direction word be the same letter size.

Examples of letter style and minimum letter and numeral sizes on an Advance Guide sign are shown in Figure 4‑10.

Letter style and minimum letter and numeralsizes on an Advance Guide sign. (click in image to see full-size image)

Figure 4-10. Letter style and minimum letter and numeral sizes on an Advance Guide sign.

Letter Spacing

The amount of space between letters and numerals in a word message varies with the shape, size, and style of letters. The Clearview 5WR alphabet has been developed with extensive letter spacing combinations to optimize the legibility of individual letter combinations. The letter spacing built into the Clearview font should be used for the design and fabrication of freeway guide signs.