James Wright

Susan T. Chrysler

Alicia Williams

Past research assessing sign comprehension has often employed methodologies such as simple, self-paced paper and pencil tests that ask "what do you think this sign means?" These studies often fail to detect any improvement in comprehension from one sign to another, newly designed version of the same sign. This experiment evaluated the effectiveness of different display methods to assess traffic sign comprehension. While a driving simulator allows fine measurements of driving performance, it is an expensive and inconvenient way to present signs for a simple multiple choice comprehension test. One of the aims of this study was to identify less expensive and more portable methods of testing sign comprehension. Different sign designs were compared which indicated freeway-to-freeway splits, lane drop exits, and left exits. A sign comprehension test was administered via the following methods: 1) Self-paced paper and pencil test of images of signs in a road context; 2) Self-paced paper and pencil survey of images of signs in isolation; 3) Limited exposure time computer presentation of the signs in road context; 4) ) Limited exposure time computer presentation of the signs in isolation; 5) Video loop of a driving scene generated by driving simulator software presented in a classroom; and 6) Fully interactive driver-in-the-loop presentation of the signs in appropriate roadway scenes in a wrap-around simulator. Results showed that for simple bold messages, the time-limited presentation media all performed similarly. The video presentation seemed to suffer some clarity reduction for text-heavy guide signs. The self-paced paper tests, as used in much previous work, showed higher comprehension scores for certain sign types.

3D Visualization as a Tool to Evaluate Sign Comprehension

Paul John Carlson

H. Gene Hawkins

A closed course nighttime legibility study measured legibility distance for 6-in. letters using Highway Series D and two experimental fonts, Clearview Condensed Road and a D-Modified font. The Clearview font has a thinner stroke width than Series D and was used for white-on-green signs. The D-Modified font has a thicker stroke width than Series D and was used for black letters on white, yellow, and orange backgrounds. Three types of retroreflective sheeting were tested: ASTM Types III, VIII, and IX.

Susan T. Chrysler

Books

Your next favorite book is out there