IDS Project Update on Human Factors and Simulation (Geometry Completed)

Human Factors 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

Task Analysis Detect intersection Decelerate and enter correct lane Signal if intending to turn Detect and interpret traffic control device Detect traffic and pedestrians Detect, perceive, and monitor gaps Accept gap and complete maneuver Continue to monitor intersection

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 Suggests drivers have problem Detecting gaps Perceiving gaps Judging gaps

Information Needs A. Vehicle Detection B. Convey speed/distance/arrival time C. Measure/convey gap D. Judge “safe gap”, display location

High Risk 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)

Collision Countermeasure System Prince William Co., Virginia Thru-STOP at two 2-lane roads Focus on warning major approach Data Collected: Speed (intersection arrival, reduction) Projected time to collision (PTC)

Human machine interface evaluated for Collision Countermeasure System (CCS) Prince William County, Virginia  Aden road (major) & Fleetwood Drive (minor) intersection located on plateau with restricted sight distances.  Drivers on minor leg often had difficulty sensing safe gap On minor legOn major leg

Collision Countermeasure System (minor approach) (major approach)

Methods & Findings Collected data before, acclimation, 4-mo., & 1-yr. after installation Results: Sizeable novelty effect Smaller number of high-speed vehicles Encouraged safer driving in presence of minor road traffic One crash during inoperative period

Intersection Collision Avoidance Warning System Norridgewock, Maine Thru-STOP at two 2-lane roads Focus on warning minor approach Data: Observational techniques Surveys

Methods & Findings Observational: Traffic Conflict Technique (TCT) Swedish Technique (adds Time to Collision) Results: Reduction in conflict potential  Half of drivers waited for sign  Half proceeded after vehicle passed through intersection No reduction main road speeds More queued traffic on minor approach

Limited Sight Distance Warning Signs Gwinnett County, Georgia 18 Thru-STOPs at two 2-lane roads Chosen based on minimum sight distance guidelines & reported problems Warnings for major &/or minor approaches Signs considered interim solution

STOP

Methods & Findings Comparison of crash records 3-yrs. before to 3-yrs. after installation Crashes reduced from 7 to 1 At one Intersection Most others reported 0 crashes Overall inconclusive findings Many variations of system Low crash rates

Relevant ITS Concept- COMPANION Two 2-lane, One 3-lane highway Variable flashing modes depending on hazard

COMPANION Manually activated (for study) Simulated truck break-down Results: Reduction in speed Harmonization of speed over lanes Reduction in all types of crashes Greater effects for drivers in slow lanes

Simulation Construction Data (TH52 and CSAH9) Road geometry Elevation profile Ditch Profile Digital Elevation Model (50m) Field and terrain Onsite survey Furniture Reality check

Time Constraints Compression of project time line necessitated (1) parallel tasks, and (2) reduced effort for realism. Focus was given to target site within simulated “loop”. Emphasis on geometry.

Actual

Simulated

Next Step Interface proposals generated. *Collect comments from experts. Collate and nominate interface candidate. Simulate candidate. Design experiment. Simulate scenario. *Pilot study. Conduct study Analyze and report.