Visual Distraction Effects of In-Car Text Entry Methods: Comparing Keyboard, Handwriting and Voice Recognition

Three text entry methods were compared in a driving simulator study with 17 participants. Ninety-seven drivers' occlusion distance (OD) data mapped on the test routes was used as a baseline to evaluate the methods' visual distraction potential. Only the voice recognition-based text entry tasks passed the set verification criteria. Handwriting tasks were experienced as the most demanding and the voice recognition tasks as the least demanding. An individual in-car glance length preference was found, but against expectations, drivers' ODs did not correlate with in-car glance lengths or visual short-term memory capacity. The handwriting method was further studied with 24 participants with instructions and practice on writing eyes-on-road. The practice did not affect the test results. The findings suggest that handwriting could be visually less demanding than touch screen typing but the reliability of character recognition should be improved or the driver well-experienced with the method to minimize its distraction potential.