1. Integrated Vehicle-Based Safety Systems (IVBSS): Crash Warning Integration Challenges Jim Sayer, Ph.D. University of Michigan Transportation Research Institute Human Factors Division

2. Current AVST Interfaces n Driver assistance/warning systems are slowly coming to market for light vehicles o Lane departure warning o Forward collision warning/mitigation n Generally these new systems are offered in isolation o Relatively “easy” to contend with one system o “Only one system, only one alert, only one response”

3. Future AVST Interfaces n Interfaces, and warning strategies, vary widely o Use of visual, audio or haptic modalities o Warning only, warn and intervene n What happens when multiple warning systems are on one vehicle? o Lane departure, lane change/merge, forward collision, curve speed, etc. warning systems

4. The Integration Challenges n Choice reaction time task o More than one stimulus alternative, more than one response alternative n How do you accurately convey the warning o Where is attention needed, or possibly how to react o Will drivers respond appropriately to multiple rare events n How will warnings be arbitrated? o When multiple threats exist, which warning is presented o Can warnings be effective in series

5. The Integration Challenges n Can adjustments be made to multiple systems? o Sufficient space, driver understanding and recall o Do adaptive systems have to provide any adjustment n Can multi-staged warnings be used? o Imminent only to reduced false/nuisance alarms o Two stage warnings to increase driver familiarity n What are the cumulative effects of warnings? o Might the total number of warnings overwhelm drivers o Could one marginal system negate trust in other systems

6. Some Current Efforts n Limited guidance is available o Either basic and applied research o Battelle report n Integrated Vehicle-Based Safety Systems Field Operational Test (IVBSS FOT) o Cooperative agreement between U.S. DOT and a team led by UMTRI o Integrate lane departure, lane change/merge, forward collision, curve speed warning o In both passenger cars and commercial trucks

7. IVBSS Sensor Configuration

8. Some IVBSS Research Questions n When there are multiple threats should: o Only 1 warning be presented or, o Subsequent warnings presented with a delay n Auditory warning characteristics: o Can warning localization convey threat type o Effects of repetitions and pauses in warnings o Urgency vs. annoyance trade-off o Recognition and reaction time to earcons vs. more abstract tones

9. T&L 1 T&L 5 LDW Imminent FCW Imminent RDCW Simulator Rumble Vorad Alert 1 LCW rumble LDW rumble 2 Alert 22331312 Alert 1211211 Alert 12312311 Alert 12322122 Alert 12133322 Alert 11321321

10. Earcons vs. Abstract Tones n Lane departure examples: o earcon abstract n As a group, earcons: o Took less time to learn, o Had the fewest number of errors, o Had the shortest reaction times

11. Simulator Testing n Examine responses to multiple warnings o Warning confusability o Varied timing between warnings n General strategy of grouping warnings o Warnings associated with longitudinal control Forward crash warning, curve speed warning Decrease your speed o Warnings associated with lateral control Lateral drift warning, lane change/merge Remain in your lane

12. Overall n Integrated warning systems interfaces pose a significant challenge n There very little research in this area n Training will become increasingly important o Example anti-lock braking systems n Common approaches across the industry will become increasingly important n Shift toward crash mitigation over warning systems will help

13. Questions? jimsayer@umich.edu