Loading in 2 Seconds...
Loading in 2 Seconds...
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@umich.edu www.umich.edu/~driving Nissan Motor Company Nissan Research Center
Practical Lessons from InfoMan
Paul Green & Norimasa Kishi
University of Michigan
Ann Arbor, Michigan
Nissan Motor Company
Nissan Research Center
* Workload manager conceived and developed
* Proprietary workload algorithm
* UMTRI provided a background literature
review to support its development
* UMTRI was a collaborator in its evaluation
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.”
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
Rating ** important!
SD of steering wheel angle
SD lane position (sim only)
Headway (time and distance)
SD headway (sim only)
Speed drops (sim only)
Fraction of detected signals
Most use TLX to rate task workload/difficulty
- well researched
- used by driving researchers
- has NASA name
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
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
6. Driving 20 miles an hour faster than traffic on an expressway
4. Driving 10 miles an hour faster than traffic on an expressway
2. Driving on an average road under average conditions
1. Driving on an easy road with no traffic, pedestrians, or animals while perfectly alert
Extremely somewhat neither safe somewhat extremelysafe safe nor unsafe unsafe unsafe
1. Drive on an average road under average conditions
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?
Most ratings are 2-6, so most ratings are relative to speed (unidimensional).
* 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)
20% short tasks, 40% long tasks > individual safety thresholds
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)
Boyle, Dienstfrey, and Sothoron (1998). National Survey of Speeding and Other Unsafe Driving Actions (NHTSA report)