This research was conducted to develop and test a personal computer-basedstudy procedure (PCSP) with secondary task loading for use in human factors laboratory experiments in lieu of a driving simulator to test reading time and understanding of traffic control devices such as changeable message sign (CMS) messages. The importance of this research effort was to show that a PCSP approach could be used to achieve comparable results as a driving simulator approach. Therefore, a larger sample of subjects can be tested with the PCSP at a much lower cost. A secondary loading task was developed for the PCSP where subjects were shown CMS messages while simultaneously deactivating randomly displayed buttons in an on-screen control panel. The secondary task workload could be varied by increasing or decreasing the rate the buttons appeared in the control panel. One-hundred-twenty-six subjects were tested within the PCSP and in a fixed-base driving simulator.The subjects were subdivided into three subgroups to compare performance between the driving simulator and the PCSP for alternative CMS messages. Analysis revealed that essentially the same conclusions were reached with respect to differences in average reading times for each of the three PCSP button display rates in comparison to those reached using the TTI driver simulator.
Abstract