1. Human Factors Progress IDS Project Nicholas Ward Jason Laberge Mick Rakauskas HumanFIRST Program

2. Human Factors Tasks Analyze problem Task analysis “What are drivers doing wrong?” “Who is at most risk?” Driver model (Information Process) “Why are they doing it wrong?” “What information could support correct behavior?” Previous solutions “What has not worked before?” Simulate case site Propose interfaces and simulate candidate Evaluate candidate interface

3. Human factors issues In Minnesota, most drivers stop before proceeding (Preston & Storm, 2003) 57% stopped in 2296 rural thru-STOP accidents 87% of right angle crashes at US 52 and CSAH 9 occurred after the driver stopped NOT a violation problem Instead, a gap acceptance problem Detecting vehicles and presence of gaps in traffic Perceiving gap size Judging safe gaps

4. Information Needs A. Vehicle Detection B. Convey speed/distance/arrival time of lead vehicle C. Convey lead gap size D. Judge “safe gap” (and display location in traffic)

5. Target Population Older drivers (> 65 years) have a high crash risk at intersections Drivers > 75 years had greatest accident involvement ratio (Stamatiadis et al., 1991) Drivers > 65 years 3 to 7 times more likely to be in a fatal intersection crash (Preusser et al., 1998) Drivers > 65 years over-represented in crashes at many rural intersections in Minnesota (Preston & Storm, 2003)

6. Intersection Task

8. Elevation

9. Interface Task Human factors analysis of crash problem Task Analysis Driver Model Abstraction Hierarchy Expert panel review of concepts Everyone had own perspective No consensus Candidate set proposed based on information needs: Detect vehicle Present speed and time Present gap size Specify safe gap Sign formats consistent with MUTCD (shape, color)

10. Four Prototypes Static Warning New warning sign Sign conforms to human factors criteria for warning Labels Low cost solution (baseline) Split-Hybrid Arrival time countdown for lead vehicle Prohibitive symbol relative to maneuvers based on near and far-side traffic conditions. Hazard Beacon Flashing red beacon activates when intersection is unsafe System tracks speeding or arrival time of lead vehicle Speedometer Speed monitor for lead vehicle Flashes red when near or far-side vehicle is speeding

11. Variable Message

12. Modifications Hybrid will be used in two formats: “Combined” on right nearside by stop sign “Split” on left nearside and right farside (median). Beacon is replaced with a (flashing) VMS message.

13. Evaluation Simulation required Interfaces do not exist in real world Need flexibility to modify interfaces Need control over traffic (and environment) conditions Need repeated exposure to same conditions to produce reliable data Simulation limits Not a traffic simulator Calibration with real world data from on site instrumentation Limitations to “size” of experiment Time intensive to implement and validate

14. Your Task (mickr@me.umn.edu) Focus on function, not design What approach should be taken to obtain MUTCD approval? NOTE: 1. Not MUTCD 2. Not final version 3. Token traffic 4. Improved algorithms 5. Resolution limitations

15. Conclusion Task Completed: Intersection selected and simulated with high Geospecific accuracy. Task On schedule: Interface concepts generated based on human factors analysis and preliminary review by experts. Interface candidates simulated in driving simulator environment. Demo scheduled for project panel.