Basically, HYSIM consists of a car cab that provides a realistic driving environment, a variety of computers to control the simulation, and two primary visual systems.
The graphics computer also controlled the vehicle dynamics of the HYSIM.
All of the electrical wiring for the HYSIM I/O devices was routed through the control center to facilitate troubleshooting and the addition of ancillary devices.
This first-generation HYSIM represented the state of the art in driving simulation in the United States, and although highly sophisticated for its time, it provided a relatively sterile visual environment.
Many of these studies required increased capabilities in the HYSIM, and over the years, additional modules were added.
Individual subsystems in the HYSIM were also upgraded over the years.
Next, the experimenter described the HYSIM car controls, read the study instructions to the subject (appendix F in the final report), and gave the subject an overview map of the practice route.
The subject was given a brief break while the main drive was loaded into the HYSIM computer.
During the drive, the experimenter monitored the subject's progress from the control room adjoining the HYSIM laboratory.
The magnitude of the latter result appears to be an artifact related to the HYSIM itself.
The simple audio group performed much better than the simple visual group, probably because the spoken message attracted more attention in the quiet environment of the HYSIM.
It is possible that some subjects simply had trouble in correctly identifying the correspondence between the electronic map and the roads in the HYSIM.