Abdulilah Z. Zineddin’s research while affiliated with Pennsylvania State University and other places

Storefront signs are often the end point of the information system travelers use to navigate the street and highway system to arrive at commercial destinations. To test the supposition that larger parallel signs would be as visible as smaller perpendicular signs, a variety of on-premise signs were tested under real-world conditions to determine their detectability and legibility. Using an open-field research design conducted on public roadways in a small downtown area and along a commercial strip development zone, 120 older and younger subjects viewed signs during both day and night conditions, with particular attention paid to sign orientation, operationally defined as parallel (i.e., being parallel to the roadway) versus perpendicular (i.e., being perpendicular to or facing oncoming traffic). Sign orientation was investigated by comparing perpendicular signs to parallel signs that were two and three times larger than the perpendicular signs with proportional increases in copy size. Contrary to most sign codes, the results indicate that perpendicular signs are significantly more detectible and legible than are larger parallel signs.

This paper reports the findings of research conducted for the Pennsylvania Department of Transportation (PennDOT) to develop customer-based standards for ride quality on four functional classes of highway: Interstate highways, other national highway system (NHS) roads, secondary roads with average annual daily traffic (AADT) greater than 2,000, and secondary roads with AADT less than 2,000. The field work, in which subjects evaluated the ride quality of predetermined test sections of pavements, was conducted in six Pennsylvania counties to incorporate a variety of settings across the state. These subjective ratings were regressed on international roughness index (IRI) values for each of the four highway classes and revealed a fan-shaped pattern in which motorist satisfaction with ride quality dropped off with increased roughness most sharply on Interstate highways, less so for other NHS roads, and still less for secondary roads. PennDOT's current standards for what constitutes good ride quality for each of the four road types equates closely with the 70% level of motorist satisfaction, whereas the standards for excellent ride quality coincide with the 90% motorist satisfaction level for all but the lower-volume secondary roads. The results also suggest that motorist satisfaction with ride quality is extremely sensitive to IRI in rural settings, moderately sensitive to IRI in urban settings, and less so in major metropolitan suburban areas. This pattern is the reverse for NHS roads, and for secondary roads motorist satisfaction is very sensitive to IRI in rural areas and less so in urban and suburban areas. From these results, PennDOT could consider adopting more ambitious ride quality standards, targeting even higher levels of customer satisfaction. However, adopting such standards would require a careful analysis of the cost implications, which is beyond the scope of the research reported here.

This paper reports the findings of research conducted for the Pennsylvania Department of Transportation (PennDOT) to develop customer-based standards for ride quality on four functional classes of highway: Interstate highways, other national highway system (NHS) roads, secondary roads with average annual daily traffic (AADT) greater than 2,000, and secondary roads with AADT less than 2,000. The field work, in which subjects evaluated the ride quality of predetermined test sections of pavements, was conducted in six Pennsylvania counties to incorporate a variety of settings across the state. These subjective ratings were regressed on international roughness index (IRI) values for each of the four highway classes and revealed a fan-shaped pattern in which motorist satisfaction with ride quality dropped off with increased roughness most sharply on Interstate highways, less so for other NHS roads, and still less for secondary roads. PennDOT's current standards for what constitutes good ride quality for each of the four road types equates closely with the 70% level of motorist satisfaction, whereas the standards for excellent ride quality coincide with the 90% motorist satisfaction level for all but the lower-volume secondary roads. The results also suggest that motorist satisfaction with ride quality is extremely sensitive to IRI in rural settings, moderately sensitive to IRI in urban settings, and less so in major metropolitan suburban areas. This pattern is the reverse for NHS roads, and for secondary roads motorist satisfaction is very sensitive to IRI in rural areas and less so in urban and suburban areas. From these results, PennDOT could consider adopting more ambitious ride quality standards, targeting even higher levels of customer satisfaction. However, adopting such standards would require a careful analysis of the cost implications, which is beyond the scope of the research reported here.

Although highly legible, the National Park Service's (NPS) Clarendon font produces sign legends that can be 10% to 20% longer than those depicted in conventional sans serif fonts. Placing these wider signs on narrow park roads and in urban historic districts can be prohibitive. To address this problem, a project was initiated to create a new NPS Roman-style (i.e., serif) font that requires less horizontal sign space than Clarendon while improving sign readability and retaining Clarendon's unique signature quality. The present study also evaluated a set of guide sign arrows to select the most legible for use on NPS guide signs. Three candidate typefaces were developed for daytime and nighttime field evaluation with 72 older and younger subjects. From the results of the evaluation, a fourth font was created and field tested with 12 additional subjects. Words created with the fourth font (NPS Roadway) were 5% to 11.5% shorter than those created with Clarendon. Further, subjects were able to read these words at 10.5% longer average threshold legibility distances than the same words composed in Clarendon. The relative legibility of 12 candidate guide sign arrows was evaluated in an outdoor field study. Forty-eight subjects participated in the daytime, and 32 subjects viewed the arrows at night. There were statistically significant differences in legibility distance among the various arrow shapes. The arrow ultimately recommended for use on NPS road guide signs performed 18% better than the FHWA "standard arrow."

Highway sign font legibility has been studied extensively over the past 50 years; however only limited research has been conducted on the range of fonts used for commercial signage. While earlier research has demonstrated that some of these fonts are more legible than others, difficulties have arisen in ascribing these differences to visual factors alone. The objective of this experiment was to determine if some of the font superiority effect is due to the level of font familiarity. Visual acuity thresholds for letter and words displayed in three fonts were recorded for a group of 72 younger and older subjects. The subjects read aloud two pages of text displayed in those fonts. Acuity thresholds for the three fonts were then reevaluated. The results showed that familiarity with a specific font significantly influences that font's legibility and that this effect was greater for older than younger subjects.

Numerous studies have evaluated the legibility of various fonts displayed in small print. There has also been a great deal of research into the legibility and recognition of standard highway sign alphabets. There has, however been no attempt to empirically determine large format distance legibility for the growing number of fonts currently available to non-transportation sign manufacturers. The present study systematically evaluated the letter legibility of a set of fonts that are consistent with commercial (e.g., storefront), industrial, transit, and highway signage. The fonts were evaluated in a laboratory setting. Individual test charts were designed for each of the fonts based on the standard Snellen distance visual acuity chart. Recognition acuity thresholds for each of the fonts yielded the minimum visual angle of letter height necessary for their resolution. The relative legibility of each font is discussed, as is the effect of font choice on sign size, and theoretical issues related to critical detail for letter recognition acuity.

Thesis (Ph. D.)--Pennsylvania State University, 2002. Microfilm (positive).