Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


Safety Sciences

First Advisor

Christopher Janicak, Ph.D., CSP, CEA, ARM

Second Advisor

Wanda Minnick, Ph.D., CSP

Third Advisor

Helmut Paschold, Ph.D., CSP, CIH, PE (Texas)

Fourth Advisor

Shane McLaughlin, Ph.D.


The objective of this study was to use mobile eye tracking methodology to examine the effect on a motorcycle appliqué’s conspicuity to determine if oculomotor capture was achieved by three LED brake lamp treatments: (1) 83.30 millisecond flash frequency sequence, (2) 117.50 millisecond flash frequency sequence, and (3) the continuous state. This study is based upon the findings of Wierwille, Llaneras, and Neurauter (2009). Using subjective impression rankings, Wierville et al. (2009) determined the optimal attention-grabbing flash frequency for LED automotive tail lamp assemblies is 83.30 milliseconds, and 117.50 milliseconds is a near-optimal flash frequency, compared to the continuous state. Research further suggests oculomotor capture of visual attention can be achieved by the abrupt introduction of a new, relevant, sensory-based visual stimulus.

Motorcycle conspicuity research indicates the low conspicuity of a motorcycle is a major cause of multivehicle accidents involving motorcycles. A literature review suggests no testing has been done to determine whether flashing a motorcycle’s brake lamp significantly increases the conspicuity of a motorcycle.

During data collection, participants were positioned in a static vehicle and engaged in the secondary task of texting. Texting while driving is a major causal factor for rear-end collisions among distracted drivers (Carney, McGehee, Harland, Weiss & Raby, 2015; Fitch et al., 2013).

An analysis of visual behavior responses across the three treatments to determine the effect of the treatments on the conspicuity of the motorcycle appliqué could not be conducted because only one treatment, the 83.30 millisecond flash frequency sequence, generated an oculomotor capture response. The 83.30 millisecond flash frequency achieved oculomotor capture with three of 16 participants exposed to this treatment.

Analysis of the subjective impression rankings of the LED brake lamp’s ability to capture the participant’s visual attention at a 100-foot intravehicular distance found a statistically significant difference between the means of the 83.3 millisecond flash frequency sequence and the continuous condition. However, analysis of the subjective impression rankings at a 30-foot intravehicular distance found no statistically significant difference across the three LED brake lamp treatments.