The impact of secondary task cognitive processing demand on driving performance.

Area of Science:

• Human Factors
• Transportation Safety
• Cognitive Psychology

Background:

• Inattention is a primary cause of driver errors and crashes.
• In-vehicle information systems (IVIS) can contribute to driver inattention through cognitive capture and uncertainty buildup.

Purpose of the Study:

• To investigate how specific IVIS task characteristics affect driving performance.
• To identify IVIS design elements that may lead to uncertainty buildup and cognitive capture.
• To provide data for improving IVIS design and reducing driver error.

Main Methods:

• Conducted three on-road studies using instrumented passenger and tractor-trailer vehicles.
• Recruited diverse driver groups: young, middle-aged, and older passenger vehicle drivers, and middle-aged and older commercial vehicle operators.
• Exposed participants to IVIS tasks varying in information density, decision complexity, format, and modality (visual/auditory) while driving.

Main Results:

• Tasks with multiple decision-making elements significantly impaired driving performance for both passenger and commercial vehicle drivers, regardless of presentation modality.
• Compared to simpler tasks, complex IVIS tasks negatively impacted driving performance.
• Findings indicate a substantial negative effect of task complexity on driver performance.

Conclusions:

• IVIS tasks with multiple decision-making elements pose a significant risk to driving safety.
• Reducing decision complexity in IVIS design is crucial for mitigating driver error.
• Implementing these findings can lead to safer IVIS designs, preventing phenomena like uncertainty buildup and cognitive capture.