Drivers use highway guide signs to navigate safely. While the retroreflective materials used for these signs have changed dramatically in the last 50 years, the fonts used on these signs have not. In the 1990's a new highway sign font, ClearviewHwy was developed and tested. In 2004, the FHWA issued an Interim Approval for the optional use of the Clearview font for positive contract legends on guide signs. The newly released 2009 FHWA Manual on Uniform Traffic Control Devices did not include Clearview but left the Interim Approval in force, because more research is needed on highway sign fonts. Clearview font letters were developed as a specific effort to improve legibility and reduce halation of highway sign legends. Halation is a particular problem for older drivers and those with reduced contrast sensitivity and often occurs with the use of high brightness retro-reflective materials. Halation can occur when headlights hit highly reflective sign lettering and temporarily cause the letters to become so bright that they lose their familiar shape. The Clearview letters were designed to have more interior space, so that the glow would not cause the letters to completely lose their shape. Penn State University conducted the first nighttime research on Clearview in the early 1990's demonstrating its efficacy. The version of Clearview font designed to subsitute for Series E (Modified) is Clearview 5W which was found to be more legible than Series E( Modified) but required more sign space. To address this issue, the developers of Clearview created a modified version, Clearview 5WR designed to produce the same average work lengths as Series E (Modified). Subsequent research completed at the Texas Transportation Institute (TTI) found that Clearview 5WR provided, on average, the same footprint as Series E (Modified) but with significantly longer legibility distances. The Clearview font family is a proprietary font requiring a sizeable investment to a state agency adopting the font. Several other states have noted the following: 1. Signs using legends in the Clearview fonts sometimes require larger dimensions than the same message using the corresponding Highway fonts. The increased dimensions of signs require reengineering of the sign structure. 2. The geometry and construction of the fractions, whose legibility is addressed in the Clearview fonts are contrary to the guidelines of the federal MUTCD manual. 3. The federal standard allows for the use of Cardinal Directions with a larger first letter. The Clearview fonts do not address this issue. When multiple sizes of text are used in the same word, the distance between letters is undefined, therefore becomes 0. 4. The MUTCD specifies legends on some signs to have reduced or expanded spacing between letters. If the font is compressed through reduced spacing, the word compression does not hold as the font is used or transferred between different applications. There are other available highway fonts that have been created based on the Series E (Modified) Highway font. These new fonts have been developed with input from some state DOT's. It appears that the new fonts provide improved performance over the Highway fonts without the concerns and issues identified above, including the pricing issue.

The objective of this study is to conduct a field evaluation of new available highway fonts versus the Series E (Modified) and Clearview 5WR fonts for use on guide signs. This study will provide the analysis necessary for decision to be made on inclusion of fonts for older drivers in the MUTCD. In previous studies comparing Clearview fonts to previously used types, legibility distance, the distance at which a subject can read an unknown word, has been a robust measure of effectiveness. Researchers believe that in order to test the proposed font against the current standard, nighttime data collection in which participants drive an instrummented vehicle along a closed course while researcher's record data would be most conducive.

Work Tasks: Task 1: Kick-Off Meeting and Discussion of Work Plan Task 2: Review available highway fonts modified base on Series (E) modified font and select those appropriate to experiment with. The available fonts must be in the public domain and available in both electronic and table formats. Task 3: Experiment Design and Equipment Set-Up At least two test groups shall be included: young (28-54) and old (55+). Participants must be drivers. An appropriate statistical sampling of participants shall be used. Signs must be full-size with high performance retro reflective sheeting and are to be provided. The research team will provide an appropriate testing facility for the dynamic nighttime study. Task 4: Data Collection Data collection shall take place during the day and night, with an emphasis on nighttimes. Data collection will include legibility distance as the primary measure of effectiveness. Task 5: Data Analysis The appropriate descriptive statistics as well as multivariate statistics shall be performed with the data. Task 6: Final Report A final report will be prepared within 15 months of the start of the contract. Deliverables: A single stand alone document including the study design and findings with respect to the performance of the tested highway fonts versus the currently used Series E (Modified) and Clearview 5WR fonts will be submitted to the sponsor.

The recommended participation level is $15,000 per year for 2 years. Mn/DOT, WisDOT, 3M, and Avery Dennison will provide some or all of the signs.