Radio Tuning Effects on Visual and Driving Performance Measures: Simulator and Test Track Studies

Existing driver distraction guidelines for visual-manual device interface operation specify traditional manual radio tuning as a reference task. This project evaluated the radio tuning reference task through two activities. The first activity consisted of a static evaluation of the features and layouts of 12 original equipment vehicle radios. The second activity consisted of an experiment in which naÏve participants drove five models of vehicles on a test track while performing manual radio tuning tasks. Driving performance measures and eye glance behavior were examined during radio tuning and baseline (no secondary task) periods. Results showed differences between task and baseline periods in most measures as a function of radio design. Results of the test track radio running experiment were evaluated along with experimental data for radio tuning obtained in a driving simulator by NHTSA. Similar results were found for most eye glance measures. The data suggest the following visual demand acceptability criteria based upon driver 85th percentile radio tuning performance: - Individual eye glances away from the forward road scene should not exceed 1.3 seconds, and - Total eyes-off-road time to perform an entire task should not exceed 12.1 seconds. For compatibility with occlusion testing, these time values should be rounded off to multiples of 2.0 seconds. This gives task acceptability criteria of individual eye glances away from the forward road scene not exceeding 2.0 seconds and total eyes-off-road time to perform an entire task not exceeding 12.0 seconds.