Until recent years, the design of primary and secondary controls for automobiles followed a fairly established pattern. Driver expectations regarding their size, shape, and location were relatively high. With the proliferation of electronics within the passenger car, especially involving secondary controls (radio, heater, etc.), such expectations no longer hold true. Yet older drivers, encumbered as they are with gradually deteriorating visual capability, and an increasing difficulty with tasks involving excessive use of short term memory and divided attention, rely upon control expectations to reduce eye-off-the-road time. For this reason, they are more apt to select a "traditional" display in product reviews. This paper is an attempt to bring an understanding to the visual and cognitive changes that drivers experience once they pass the age of 50, and to suggest guiding principles for the design of primary and secondary controls that might accommodate these changes. (A) For the covering abstract of the conference, see IRRD 837684.
Abstract