# Presentation: 773342

## Assessing the Safety of Infotainment Systems Used While Driving: 

**Practical Lessons from InfoMan**
- Paul Green & Norimasa Kishi

- University of Michigan
- UMTRI
- Ann Arbor, Michigan
- 48109-2150 USA
- _[Pagreen](mailto:Pagreen@umich.edu)__[@](mailto:Pagreen@umich.edu)__[umich](mailto:Pagreen@umich.edu)__[.edu](mailto:Pagreen@umich.edu)_
- www.umich.edu/~driving

- Nissan Motor Company
- Nissan Research Center
- Yokosuka, Kanagawa
- 237-8523, Japan
- n-kishi@mail.nissan.co.jp

## Slide 2

## InfoMan (Information Manager)

-        by Nissan
- * Proprietary workload algorithm
- * UMTRI provided a background literature
-       review to support its development
- * UMTRI was a collaborator in its evaluation

**InfoMan (Information Manager)**

## What Did We Do?  - Issues

**Experiment 1 (on the road, 2002 Q45):**
- 1. Can an information manager reduce the risk of driving?
- 2. How can the Nissan workload metric be improved?
**Experiment 2 (DriveSafety driving simulator):**
- What is the relationship between menu depth & primary task demand?
- 2. Is PDT sensitive to workload?
- 3. How do the real and simulated results compare?

## What Did We Do? - Driver Tasks

- Hypothetical 4 /level & real interfaces
- * Example 3 step
-   “Set the navigation heading to north up.”
- * Example 6 step
-   “Set the map background display to bright.”

## Real

**(Exp. 1)**

**Simulated**
**(Exp. 2)**

- Arterial
- Downtown
- Rural
- M-14
- (xway)
- US-23
- (xway)

- Arterial
- Downtown
- Rural
- M-14
- (xway)
- US-23
- (xway)

## Lesson 1 - Simulated Roads

- It is extremely difficult to match real roads using the current version of the DriveSafety software due to the tile architecture.
- * No 2 lane/direction expressways
- * Many missing x-way interchanges
- * No pipe bridges for signs (landmarks)
- * No easy way to add landmark buildings

## Specific Workload Roads - Experiment 2

## Lesson 2 - Test Roads

- For large individual differences (e.g., young vs. old), variable length road sections are needed.
- --> multiple out and back (return) points
- --> hard to assemble consistent, multi-road sequence
- 2. Many driving studies occur in the spring/summer construction season.  Get the schedules.
- 3. Because of traffic, data collection time-outs are needed.
- 4. Obtaining consistent data in urban areas is much more difficult than the open road, the typical case in the U.S.

## Lesson 3 - Dep. Measures - New Scale

**Rating ** important!**
*SD of steering wheel angle*
*SD lane position (sim only)*
*Headway (time and distance)*
*SD headway (sim only)*
*Mean speed*
*Speed drops (sim only)*
*Completion time*
*Response time*
*Fraction of detected signals*

**Risk**
**Driving Performance**
**Menu Task**
**Peripheral **
**Detection Task**

## Lesson 3 - New Rating Scale

- Most use TLX to rate task workload/difficulty
-  - well researched
-  - used by driving researchers
-  - has NASA name
- _But..._
- Risk .ne. workload
- Difficult to relate TLX to driving dimensions
-   (road geometry, traffic, etc.)
- Drivers need contextual anchors for rating
-   - range of ratings is uncertain -> range compression
-   - drivers forget what things were -> inconsistency

## Rating, As Risky As...

- 10. Driving with my eyes closed.  A crash will occur every time
- 9.  Pass a school bus: red lights flashing & the stop arm out
- 8.  Driving just under the legal alcohol limit with observed weaving
- 7.
- 6. Driving 20 miles an hour faster than traffic on an expressway
- 5.
- 4. Driving 10 miles an hour faster than traffic on an expressway
- 3.
- 2. Driving on an average road under average conditions
- 1. Driving on an easy road with no traffic, pedestrians, or animals while perfectly alert

**(UMTRI Scale)**

## Lesson 3 - UMTRI Risk Scale Calibration

- 2. Drive through a stop sign without slowing down
- ...
- 6. Driving today:  Perform a short task while driving on the hwy
- 7. Driving today:  Perform a long task while driving on the hwy
- * Mark the risk ratings you gave while driving (e.g., a “2”).
- * Below what value would you perform a non-urgent task?
- * Above what value would you **never** perform in-vehicle tasks?

**Lesson 3 - UMTRI Risk Scale Calibration**

- Extremely	somewhat	neither safe	  somewhat	extremely**safe****	****	**safe		nor unsafe	  unsafe	**unsafe**

## Lesson 3 - Key Points About Ratings

-  * crash prob. versus excess speed (for x-ways) ->
-  fatalities (“How many people will die” question.)
- Normalize to what is acceptable for each driver so between driver comparisons are consistent.  (Different drivers have different acceptance levels for excess speed.)
- Post-test ratings (each task length (none, 3, 6 steps), each road type) were well correlated with ratings while driving. (-> reliable)

**Lesson 3 - Key Points About Ratings**

## Example Results from Risk Ratings

- 20% short tasks, 40% long tasks > individual safety thresholds

**Example Results from Risk Ratings**

## References

**Project reports to appear, see www.umich.edu/~driving**
- Tsimhoni, Smith, and Green, (2003).  _On-the-Road Assessment of Driving Workload and Risk to Support the Development of an Information Manager_ (Technical Report UMTRI-2003-08)
- Tsimhoni, Smith, and Green, (2003).  _The Effect of In-Vehicle Task Menu Depth and Driving Workload on Task and Driving Performance_ (Technical Report UMTRI-2003-09)
**Risk Rating**
- Boyle, Dienstfrey, and Sothoron (1998). _National Survey of Speeding and Other Unsafe Driving Actions_ (NHTSA report)

## “Driver” Distraction

**“****Driver” Distraction**