Mental distractions and physical impairments can increase the risk of accidents by affecting a driver’s ability to control the vehicle. In this article, we developed a linear mathematical model that can be used to quantitatively predict drivers’ performance over a variety of possible driving conditions. Predictions were not limited only to conditions tested, but also included linear combinations of these tests conditions. Two groups of 12 participants were evaluated using a custom drivers’ reaction speed testing device to evaluate the effect of cell phone talking, texting, and a fixed knee brace on the components of drivers’ reaction speed. Cognitive reaction time was found to increase by 24% for cell phone talking and 74% for texting. The fixed knee brace increased musculoskeletal reaction time by 24%. These experimental data were used to develop a mathematical model to predict reaction speed for an untested condition, talking on a cell phone with a fixed knee brace. The model was verified by comparing the predicted reaction speed to measured experimental values from an independent test. The model predicted full braking time within 3% of the measured value. Although only a few influential conditions were evaluated, we present a general approach that can be expanded to include other types of distractions, impairments, and environmental conditions.
Benjamin L. Long is with the Department of Physical Therapy at Winston-Salem State University, Winston-Salem, NC, and is with the Human Performance and Biodynamics Laboratory of Wake Forest School of Medicine’s Department of Orthopaedic Surgery and Winston-Salem State University’s Department of Physical Therapy. A. Isabella Gillespie attends North Surry High School in Mount Airy, NC, and North Carolina School of Science & Mathematics (Online); she was associated with the Department of Orthopaedic Surgery at Wake Forest School of Medicine, Winston-Salem, NC. Martin L. Tanaka (Corresponding Author) is with Department of Engineering and Technology at Western Carolina University, Cullowhee, NC, and was with the Human Performance and Biodynamics Laboratory of Wake Forest School of Medicine’s Department of Orthopaedic Surgery and Winston-Salem State University’s Department of Physical Therapy.