12 Human Factors III: Distraction

Question 1

Definition of Driver Distraction

Answer 1

• Driver distraction occurs when inattention leads to a delay in recognizing information critical to safe driving.
• Not all off-road glances are distractions—context matters (e.g., threat assessment glances).

Example:
* Checking a navigation system might be a distraction if it delays responding to a traffic hazard.

Question 2

Cognitive Load and Driving

Answer 2

Cognitive Load Hypothesis: Cognitive load selectively impairs tasks requiring cognitive control but leaves automated actions unaffected.
* Automatized tasks like braking to a lead vehicle are less impacted than complex interactions (e.g., navigating cyclists).

Application:
* Increased cognitive load is more dangerous in complex traffic environments.

Question 3

Risk Characteristics of Visual-Manual Tasks

Answer 3

Key Factors:
1. Task duration.
2. Percent eyes-on-road (%EON).
3. Frequency of task initiation.
4. Context at task initiation.
5. Visual eccentricity (distance from driving focus).

Insight:
Longer tasks and lower %EON significantly increase crash risk.

Question 4

Eyes-On vs. Eyes-Off Road

Answer 4

Key Concepts:
* Percent Eyes-On-Road (%EON): Higher %EON reduces risk.
* Off-Road Glance Duration: Shorter glances are safer.
* Distribution of glance durations affects overall safety.
Example:
* A radio tuning task (~30% EON) has higher risk than baseline driving (~80% EON).

Question 5

Automation and Distraction

Answer 5

Key Points:
* Increased automation (e.g., ACC, AEB) leads to longer off-road glances but overall improved safety.
* Variability between drivers increases with automation, necessitating design to reduce risk variability.

Question 6

Total Task Time (TTT)

Answer 6

Definition:
* Total Task Time (TTT): The duration from the start to the end of a specific task, including all associated on-road and off-road glances.
Key Points:
* Longer TTT increases exposure to risk during the task.
* Doubling TTT roughly doubles the crash or injury risk.
* Tasks with shorter TTT and higher Percent Eyes-On-Road (%EON) are safer.
Example:
* A manual radio tuning task has a longer TTT compared to voice interaction, leading to greater risk exposure.

Question 7

Methods to Assess Driver Distraction

Answer 7

• Naturalistic Driving Studies (NDS):
• Example: UDrive project with 14,503 hours of truck data.
• Simulations:
• Virtual simulations assess risks associated with glance behaviors.
• Driver Monitoring Systems (DMS):
• Mandated in 2024 to monitor and influence glance distributions.

Question 8

Cultural and Individual Differences in Distraction

Answer 8

• Drivers in different regions exhibit varying distraction tendencies (e.g., Chinese truck drivers are more attentive).
• Large variability exists between individual drivers’ task engagement and risk behaviors.
• Takeaway:
• Driving culture and individual traits significantly influence distraction risks.

Question 9

Glance Behavior and Risk

Answer 9

Concepts:
* Glance Coding: Categorizing glances based on location and duration.
* Looming: Perceptual measure indicating the urgency of visual threats (e.g., approaching objects).

Application:
* Short, frequent glances reduce crash risks compared to long, infrequent ones.

Question 10

Designing for Safer Driver Behavior

Answer 10

Strategies:
* Encourage short, frequent off-road glances.
* Develop HMIs (Human-Machine Interfaces) to minimize distraction.
* Incorporate driver monitoring systems to maintain high %EON.
Example:
* Adjusting radio settings with voice control instead of manual interaction.