Texas/Pennsylvania DOT Studies Says Clearview Font Improves Sign Legibility

A study conducted jointly by the Texas and Pennsylvania Departments of Transportation concluded that the Clearview font increased the visibility distance for drives by 12% versus the existing Series E Modified font.

In 1994 the Federal Highway Administration determined that highway signs were no longer visible enough for a population that included older drivers. Over the next decade, the Clearview font was developed. Subsequently, the Texas and Pennsylvania DOTs conducted separate studies to see how effective the Clearview font was.

The full report on this font can be found at http://onlinepubs.trb.org/onlinepubs/trnews/trnews243RPO.pdf

Should Signs be Regulated as Lighting Devices?

The answer is a very clear “no.” An article in Signs of the Times magazine explains that electric signs are not lighting devices, per se. Their purpose is not to provide light, but to provide messages. Thus, they should not be regulated as lighting devices. Electric signs need to be bright enough to be legible, but if they’re lit too brightly, then they become less legible. Thus, the sign industry has consistently provided electric signs with appropriate brightness, in order to serve their customers. The article explains these factors in much greater detail. You can read the entire article at http://www.nxtbook.com/nxtbooks/STMG/sott_201601/index.php#/66

Sign Research Foundation Releases 4-Part Typography Executive Summary

“Typography, Placemaking and Signs,” the four-part white paper series originally released by the Sign Research Foundation in 2014, is now available, free of charge, in a four-page executive summary.

Written by the Fashion Institute of Technology’s Craig Berger, and produced by SRF, the paper includes:

The History of Typography and Place;

Environmental Typography Best Practices;

Typography and the Code—ADA and Egress Codes;

and Typography Case Studies.

This executive summary highlights three key takeaways from the report:

  • Environmental typography is a natural outgrowth of the desire for people to explore and comprehend the outside world.
  • To successfully carry a message that resonates, typography must be successful on its own as well as integrated into a complete and effective overall design.
  • Codes and regulations apply to graphic information including symbols and type, and those who understand the intricacies and overlapping governance are usually the most successful.

The complete 54-page paper can be viewed at http://www.signresearch.org/wp-content/uploads/Typography-Placemaking-and-Signs.pdf

How is the Size of Signs Measured?

The most common restriction in sign codes concerns the size of signs. This includes such considerations as the “setback,” (distance away from the road), the height and the dimensions of the sign itself. When the sign is a rectangle, and the copy fills it,  it’s easy — height x width. A 4 x 6-foot sign is 24 square feet.

But what if the sign is an irregular shape, or if the copy only fills a fraction of the sign face? What if the sign is individual channel letters on a wall? What if a backlit awning includes a logo? In all of these situations, do you measure the entire polygon, or just the portion that includes a logo or text?

What if the letters include upper- and lower-case letters, which means ascenders and descenders? Do you measure a rectangle around this “irregular” shape?

If the sign code establishes relatively small maximum sizes for signs, and measures all signs as rectangles, does this curtail creativity in design, because the merchant feels compelled to make the necessary letters as large as possible in order to achieve maximum visibility? Does this discourage round, triangular, oval and other shapes of signs?

The International Sign Association website has a section on measuring signs. You can access it at http://www.signs.org/LinkClick.aspx?fileticket=iAfIQfU-zL8%3d&tabid=1459

Penn State Study Examines Font Legibility

The Larson Transportation Institute at Penn State University conducted a study on font legibility through a grant from Gemini Inc. (Cannon Falls, MN), a manufacturer of dimensional letters. The following is the Executive Summary from the report. For information about the full report, contact Philip Garvey at pmg4@psu.edu.

Background and objectives

The enormous font selection available for on-premise signs fosters creativity, but also limitations, because of the unknown of a given font’s legibility at various distances. Although a small number of studies have broached this topic, this research effort is intended as the first to address the visibility of a large set of existing on-premise fonts.

Laboratory experiment


The study was conducted at Penn State. Sixty-four signs were tested, using 34 unique fonts. The fonts were displayed as scale-sized, one-word, on-premise signs on a high-resolution computer monitor. Sixty-four subjects from 19 to 87 years of age participated. The legibility distance of each font was determined, and the effects of age, uppercase vs. lowercase, serif vs. sans serif, word-superiority, and art/word combination were evaluated.

Age group effect

The subjects were divided into three age groups. Not surprisingly, and consistent with earlier research, the young group and the middle age group were both able to read the signs from further away than the more elderly group.

Font effect

Large differences in font legibility were found. Gill Sans uppercase provided the best legibility, while Mistral lowercase had the worst. Also, simply choosing a font with a 5-ft./in. or larger ratio of distance to letter height insures better legibility, both statistically and practically.

Case effect

For all 31 fonts presented in both upper- and lower-case conditions, the upper-case words were more legible. In 22 of those cases, that difference was statistically significant.

Serif vs. sans-serif effect

There was no statistical difference between the serif and the san-serif fonts when shown in uppercase. A statistically significant effect was found in the lower-case analysis; however the difference was not practically significant.

Font family effect

Several fonts tested had more than one “weight,” such as bold or condensed.  The upper- and lower-case fonts were analyzed separately with the following results:

  • For upper and lower case, Times Bold was significantly more legible than Times New Roman.
  • For upper and lower case, Optima Bold was significantly more legible than Optima.
  • For upper and lower case, Garamond Bold was significantly more legible than Adobe Garamond.
  • For upper case, Helvetica was significantly more legible than Helvetica Bold, Helvetica Light and Helvetica Medium Condensed. Also, Helvetica Bold was more legible than Helvetica Light. For lower case, Helvetica was more legible than Helvetica Bold and Helvetica Light.

Word superiority

The 64 words showed large differences in legibility. The most legible word was Sunday, which was more than twice as legible as the least legible word, Crawfordsville.

Words and art

All of the signs tested included words and a graphic element. In 10 instances, the graphic directly related to the word (e.g., a drawing of a flower and the word “Flower”). This relationship minimally impacted sign readability.


This research sought to determine the relative legibility distances of a large set of fonts used on on-premise signs.  It allows users to compare legibility distances and make an informed decision about which font to use on their signs. Several results are clear:

  • Although font selection can significantly impact on-premise-sign legibility, many fonts have equivalent legibility.
  • Case (upper vs. lower) sometimes, but not always, can greatly impact sign legibility. Upper case often performs significantly better than lower case, at least under this study’s conditions.
  • The choice of serif vs. sans serif alone doesn’t measurably affect legibility.
  • Font weight can dramatically impact the distance from which a sign can be read. Fonts from the same family (e.g., Times) can have dissimilar legibility.
  • Word selection can greatly impact sign legibility. Not surprisingly, simpler, shorter words can be read at greater distances, regardless of font.
  • Matching a word to an image or graphic on a sign doesn’t, generally, positively impact legibility.

What the Three Street Graphics Books Say About Signs

In 1971, the American Planning Association (APA) began distributing a book called Street Graphics and the Law, which was authored by Daniel Mandelker and William Ewald. It recommended the uncompensated taking of signs and governmental control of signs’ design, message and content.

The authors stated that their conclusions were substantially based on 1956 research conducted by Rockefeller University professor George Miller with regard to the human brain’s ability to process multiple bits of information. Yet, when Miller read the authors’ assessment of his research, he observed “The situation would be amusing if misrepresentations of my work were not being taken as the basis for enacting ordinances to control street graphics . . . I must strongly protest the distortion of my own work and must deplore the enactment of restrictions based on such an inadequate understanding of the psychological processes involved.” Miller’s 1000-word letter that denounces Street Graphics‘ interpretation of his work appeared in the April 1973 issue of Signs of the Times magazine.

In the following decade, several Supreme Court (SCOTUS) decisions overruled some tenets of the book. Subsequently, in 1988, the same authors revised the book as Street Graphics. It retreated from many of its restraint of trade recommendations, yet the majority of it remained intact.

In 2005, the third version, entitled Street Graphics and the Law, was released, and a third author, from the sign industry, was listed on the cover as a principal author. He wrote one chapter that included some Penn State legibility tables. Most of the rest of the book remained intact, but, by implication, it appeared that the sign industry endorsed the entire book.

Thus, this third version was viewed as significantly flawed, but a slight improvement over the first two versions. The question still remains, how good must good enough be? Two separate discussions of the 2005 book appear in the January 2005 issue of Signs of the Times magazine.

What are Some Guidelines for Electronic Message Center Resolution?

A critical aspect of any sign is viewing distance. The appropriate amount of detail varies greatly, depending on the distance from which the sign will be viewed. In digital printing, this “resolution” is determined by “dots per inch,” or DPI. The more closely an image will be viewed, the higher its resolution needs to be, which means the dots produced by the inkjet printer would need to be closer together, and there would be more of them within a defined space.

The same concept applies to electronic message centers. The individual LEDs function the same as the inkjet dots. The more detail you want, the more LEDs you would need with a defined space, and the decision would be based on the anticipated viewing distance. An electronic billboard 600 feet from the highway is different than an electronic message center built into the cabinet of a freestanding pole sign next to a two-lane road.

For electronic signs, this resolution is called “pixel pitch,” and it means the distance between the centers of individual LEDs, which are known as pixels. The distance also varies if the individual pixel is color (comprising different-color LEDs) or monochrome (one color). Here are some general guidelines for pixel pitch and viewing distance.

Pitch Range Viewing Distance
3-6mm up to 50 feet
6-12mm 50-100 feet
12-15mm 100-200 feet
15-20mm 200-400 feet
20-30mm 400-800 feet
30-40mm 800-1500 feet
More than 40mm More than 1500 feet

As for the size of letters and viewing distance, the standards for non-electric signs apply similarly — approximately 1 inch of letter height for every 50 feet of distance from which it would be viewed. This should be coupled with the speed of traffic. Allowing a viewing time of 20 seconds is ideal. Thus, if a car is traveling at 60 mph, the sign should be legible from a distance of 1734 feet. Generally, electric highway signs should be a minimum of 10 x 30 feet.

An article on this topic appeared in the May 2004 issue of Signs of the Times magazine.

What Difference Does an Angled Sign Make Versus a Sign that’s Parallel to the Road?

Elsewhere in this series of questions, the difference in conspicuity for parallel and perpendicular signs is calculated, along with the requisite minimum sizes for the letters of each. But what if the local sign code won’t allow a bigger sign, and not enough projection length for a legible perpendicular sign? Would a sign with at least some angle make a difference?

Frenchy’s Bistro was located on Anaheim St., a busy thoroughfare in Long Beach, California. As one of four tenants in a commercial building, it had two signs: a non-illuminated wall sign and a tri-color canopy that projected the maximum 30 inches.

As an alternative, Frenchy’s purchased a “double-faced” electric, cabinet sign, but the sign faces weren’t back to back, but angled out from the wall in a V-shape toward each other.

Before the new sign(s) was(were) installed, Frenchy’s had $279,000 in pre-tax income annually. After the sign was installed, sales increased 16% immediately. Over the next year, they increased an additional 32%. The owners surveyed their guests and determined the sign was directly responsible for 10% of all sales. The net income directly attributable to the sign for a year was $16,182. The following year, it increased to $21,360. This also meant an additional $8,865 in state and federal income tax.

Other calculations for the $5,700 sign included that its cost per thousand exposures (CPM, the standard way to compare different forms of advertising) was 15 cents. The cost per month for the sign was $121.11. At the time (2000), other CPMs were as follows:

  • A 30-second, prime-time TV ad: $18
  • A half-page, black-and-white newspaper ad: $10.80
  • A full-page, four-color magazine ad: $8.70
  • A one-minute, drive-time radio ad: $5.30
  • A 30-day, 30-sheet poster panel: $1.60

The full story appears in the September 2000 issue of Signs of the Times magazine.

What Happened in the Denny’s v. Agoura Hills Pole-sign Case?

In 1985, the city of Agoura Hills, California enacted a sign ordinance that prohibited all pole signs, with the exception of a few that were less than 6 feet tall. It included an amortization period that ended in March 1992, at which time all of the pole signs would have to come down, without any cash compensation.

Agoura Hills is bisected by US Highway 101, which runs significantly high above the city. Thus, the only way highway motorists could know that gas stations and restaurants were located below was due to the high-rise pole signs.

Burger King, for example, conducted a traffic-flow study and discovered that 88% of the motorists who passed its restaurant did so on the highway. Only 12% passed it on the road below. The Burger King was specifically built to serve highway customers. Burger King determined that 60% of its sales were directly attributable to its sign. It calculated that the loss of the pole sign would constitute a $2 million loss in profit over a 15-year period.

As for other end users, the court found that the removal of pole signs would cause 35% loss of gross revenue for both Texaco and McDonald’s. This would mean $336,000 less revenue for Texaco in the first year the pole sign was removed, and $1.1 million loss for McDonald’s in its first year.

In 1983, California attorney Bob Aran authored a statute called Section 5499, which stated, “No city or county shall require the removal of any on-premise advertising display on the basis of its height or size by requiring conformance with any ordinance or regulation introduced or adopted on or after March 12, 1983, if special topographic circumstances would result in a material impairment of visibility of the display or the owner’s or user’s ability to adequately and effectively continue to communicate with the public.”

Although the city contended that it banned all pole signs, the court found that the ordinance “plainly discriminated between tall signs and short signs.” The court also ruled that “special topographic circumstances” referred not only to natural surface contours, but also to “all non-temporary surface conditions of whatever origin.” As for visual impairment, the court said more than natural impairments (hills, trees) had to be considered, such as buildings, utility poles, etc.

The court concluded, “The evidence clearly establishes that these special topographic circumstances would materially impair the visibility of conforming signs for each plaintiff. The plaintiffs are entitled to prevail, first of all, based on the material impairment of raw visibility.” Furthermore, if the ban were enforced, the court said conforming signs would not be visible at all from the area’s freeway, and that conforming signs would not be visible to freeway motorists in time to safely exit at the off ramp.

What’s the Economic Difference Between a Perpendicular Doubled-faced and Single-faced Sign?

When a Pier 1 Imports store opened in Germantown, TN (a suburb of Memphis), in 1991, it was granted a permit for a sign that faced west-bound traffic. However, no signage was visible to west-bound traffic. A few months after the store’s opening, sales were 25% below projections, despite typical promotions, advertising and direct mailings.

Pier 1 subsequently surveyed 200 shoppers through a market-research firm about having a second sign. The responses were the following.

Are the signs helpful to you? 66% said “very helpful;” 31.5% said “somewhat helpful,” and 2.5% said “not at all helpful.”

Does the sign increase public safety? 93% said yes; 75 said no.

Does the sign affect aesthetics negatively? 91% said no; 5.5% said yes, and 2.5% had no opinion.

Is the sign more of a public benefit or a public nuisance? 90.5% said benefit; 5.5% said nuisance, and 4.5% had no opinion.

Expert appraisal determined that the gross annual income for the store would be $1.2 million with the second sign, and $1,020,000 without it. Store officials stated that overhead and the cost of merchandise being sold was $1,020,000 so, without the second sign, the store would generate no profit.

As for the community itself, Pier 1 estimated that, without the second sign, it would pay, city, county and state taxes of $76,080. With the second sign and increased sales, it would pay $104,229. Thus the tax-revenue difference for the town would be $28,000.  Presented with this evidence, Germantown officials readily granted a variance for the second sign. The full story about this variance appeared in the April 1992 issue of Signs of the Times magazine.