Description / Abstract:
The purpose of this SAE Recommended Practice is to present
design recommendations for the direction-of-motion of hand controls
found in passenger vehicles, multipurpose vehicles, and trucks.
These recommendations are based on recent and past human factors
research and are important considerations in the design of control
layouts.
Background
Drivers develop expectations regarding the operating motions of
various types of controls as a result of their accumulated
experience with automotive and nonautomotive controls. To simplify
the operation of controls for drivers, the direction-ofmotion to
operate these controls should conform to these expectations or
stereotypes. Failure to conform to direction-ofmotion stereotypes
can lead to actuation errors, longer operating times, and an
increase in driver workload.
A number of past studies have addressed the issue of
direction-of-motion stereotypes for various automotive hand
controls (1, 2, 3, 4, 8). These results indicate that the strength
of a stereotype varies with the control configuration (control
type, location, orientation, and mounting plane). SAE has recently
completed research (6,7) aimed at broadening the scope and
generality of the previous findings by addressing other control
orientations, including controls mounted on stalks and on inclined
surfaces. Some specific control functions such as power windows and
power mirrors were also studied. The SAE study demonstrated that
stereotype strength is not related to driver age, gender, or
handedness. This document is based on the SAE study, past research,
and general human factors principles (10). This document supersedes
Figure 1 of SAE J1139 (9).
Control labeling and tactile or shape coding are not addressed
in this document; however, previous research (5) has shown that
appropriate labeling and coding can improve the accuracy of control
use.