Individual Differences and Driver Response to Highway Intersections

Abstract

Along the Nation's roadways one of the most dangerous environments is the intersection. Accident investigations suggest several individual driver characteristics that may be associated with increased risk at intersections. To analyze the relationships of a number of driver characteristics to driver behavior in a controlled setting a laboratory simulation of the roadway intersection was created. Seventy-two research participants, ranging in age from 18 to 74, were measured on a battery of performance tests, administered questionnaires related to health and driving history, and exposed to a video display of approaching intersections as driver responses were measured. Each participant viewed 14 intersections containing a variety of traffic control devices. During the driving simulation portion of the research workload was assessed using six variables chosen to reflect three response modes-performance, subjective, and physiological. A MANOVA conducted to analyze the 3 (age level) by 2 (gender) factorial design indicated a main effect for both age and gender, based on three of the dependent variables-pedal response errors, speed of response, and heart rate reactivity. The responses to the intersection simulation indicated greater workloads for older drivers and female drivers. In a second phase of the data analysis stepwise multiple regressions were used to determine which independent variables, from among a set of driver characteristics, functioned as the best predictors of these performance decrements. As expected from the earlier MANOVA and univariate tests, age accounted for more variance in driver response than any single information processing variable. However, information processing variables that were most predictive of performance decrements included: field dependency, visual acuity, and depth perception.