1. OLDER AND YOUNGER DRIVER PERFORMANCE AT COMPLEX INTERSECTIONS: IMPLICATIONS FOR USING PERCEPTION- RESPONSE TIME AND DRIVING SIMULATION Professor: Liu Student: Ruby

2. Motive & Purpose Motive –Older drivers have the high accident percentage at interactions. Purpose –Using driving simulation to test older driver performance at complex intersections.

3. Reference When older drivers do the action which in left turn and gap-acceptance crashes are over- represented. (Caird & Hancock, 2002) The people who are 75 years or more, they were collision fatalities at the intersections. (Preusser et al., 1998)

4. Reference Decreasing the useful field of view can be predictors of intersection crashes. (Owsley et al., 1998) Older drivers are often miss the stop signs and stop lights at intersections. (Preusser et al., 1998)

5. Reference Perception response time (PRT) –The duration between the appearance of a situation and the initiation of braking. –(Olson, 1996) found the PRT was related to the age. –(Lerner et al., 1995) found the PRT was not related to the age.

6. Method - Participants Older driversYounger drivers People12 Driving experience52 years4 years Average annual mile20916 km per year15719 km per year Mean number of total accidents Mean was 2.8Mean was 0.83 The number of accidents in the past five years Mean was 0.42Mean was 0.75 Driving violationsMean was 0.75Mean was 0.25

7. Method – Equipment Driving Simulator Hardware and Software –The University of Calgary Driving Simulator (UCDS). –3-channel, 150-degree forward field of view vection simulator.

8. Method - Procedures Four experimental routes and each with 4 events. 4 events included: –The sudden appearance of a pedestrian during a right turn (Pedestrian) –A last-second yellow light (Yellow Light) –The unexpected appearance of a pedestrian using a grey mask to induce change blindness (Dynamic Flicker) –A vehicle violating a red light while the participant had a green light (Vehicle Incursion).

9. Results - Perception Response Time PRT was calculated based on any response made by the participants, whether the participants braked or accelerated.

10. Results - Perception Response Time Response to the pedestrian event was significant between the age groups, t(16) = - 2.118, p = 0.050. PRT to the Yellow Light event was significantly different between the age groups, t(17) = -4.508, p = 0.0001. The response to the Dynamic Flicker presentation and the sudden appearance of a pedestrian was significant, t(17) = -3.468, p = 0.003. The vehicle incursion was also significantly different between the two age groups, t(18) = -2.715, p = 0.014.

11. Results - Perception Response Time

12. Discussion - Perception Response Time and Response Patterns Overall, the younger drivers showed faster PRTs than older derivers. The decision by older drivers to continue through the intersection appears indicative of their inability to respond to the light quickly.

13. Discussion - Perception Response Time and Response Patterns This study examined complex intersections, with signs, pedestrians and other vehicles present. –Therefore, the PRT may be more reflective of the attention demands on older drivers than previous PRT studies.

14. Discussion - Simulator Sickness 40% of older participants and 14% of younger participants had the simulator sickness. The people who drop out due to simulator sickness may be more at risk for intersection collisions. (Stern & Koch, 1996) suggest that women are more effective to simulator sickness than men.