Usability of Menu-Based Interfaces for Motor Vehicle Secondary Functions

摘要

Three experiments were conducted to develop methods and data for examining theusability of secondary controls for accessing heirarchical menus system while driving. Heirarchical menu interfaces may be used in future vehicles for the operation of radio and navigation systems. In the first experiment, eight drivers performed a secondary task in an instrumented car and the UMTRI driving simulator. The real and simulated roads were not matched. There were no differences in secondary task time-related measures between contexts, but absolute validity of the primary task was not high. As in previous studies, speed variance was lower and lane variance was greater in the simulator. This experiment established that the UMTRI simulator was a reasonable context for examining the use of secondary controls. In the second experiment, two subjects drove the simulator for brief periods of time over 20 successive workdays. Secondary task performance continued to improve across the entire period, with most of the performance gains being evident by the fifth day. There were few interactions of time with test conditions, suggesting that testing across a large number of days not necessary. In the third experiment, 16 subjects drove the simulator while retrieving information using a menu system. In terms of task completion times, the number keypad yielded the best performance, with the rotary knob and the trackball tied for second, and the touchpad yielding the worst performance.