title: NEUROPSYCHOLOGICAL PREDICTORS OF SAFETY IN URBAN LEFT-TURN SCENARIOS.
abstract: Left turns at urban intersections can be dangerous, especially when views are obstructed or pedestrians are present. Impairments in driver vision, motor, and cognition functions may further increase left-turn risk. We examined this problem in a simulated environment that included left-turn scenarios to study the driving behaviors of 28 drivers, ages 37 to 88 years, six of whom had "Useful Field of View" (UFOV) impairments. Subjects also completed a battery of neuropsychological tests. The simulated drive included an urban section with six left turns in three types of scenarios: 1) a semi truck blocking the view of oncoming traffic, 2) a lead vehicle obstruction, and 3) a pedestrian crossing ahead of the turning driver. Results showed a mean (SD) of 1.46 (1.60) collisions per driver (range 0 to 7), 83% of which occurred at intersections with semi trucks. Far visual acuity, contrast sensitivity, UFOV, Mini Mental State Examination, Trail-Making Test Part B, the Wisconsin Card Sort task, and age were all associated with the total number of collisions (Pearson correlation magnitudes between 0.37 to 0.77; p-values<0.05). Spearman correlations were less significant. Findings indicate that visual obstruction by on oncoming semi-truck is a particularly dangerous left-turn situation.
authors.affiliation: Dept. of Biostatistics, Univ. of Iowa College of Public Health, Iowa City, Iowa, USA.
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Dawson
authors.affiliation: Dept. of Biostatistics, Univ. of Iowa College of Public Health, Iowa City, Iowa, USA.
authors.forename: Lixi
authors.initials: L
authors.lastname: Yu
authors.affiliation: Dept. of Neurology, Univ. of Iowa Carver College of Medicine, Iowa City, Iowa, USA.
authors.forename: Kuan-Hua
authors.initials: KH
authors.lastname: Chen
authors.affiliation: Dept. of Neurology, Univ. of Iowa Carver College of Medicine, Iowa City, Iowa, USA.
authors.forename: Michelle
authors.initials: M
authors.lastname: Rusch
authors.affiliation: Dept. of Biostatistics, Univ. of Iowa College of Public Health, Iowa City, Iowa, USA.
authors.forename: Amy M
authors.initials: AM
authors.lastname: Johnson
authors.affiliation: Dept. of Neurology, Univ. of Iowa Carver College of Medicine, Iowa City, Iowa, USA.
authors.forename: Nazan S
authors.initials: NS
authors.lastname: Aksan
authors.affiliation: Nissan Research Center, Nissan Motor Co., Ltd., Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Sunda
authors.affiliation: Nissan Research Center, Nissan Motor Co., Ltd., Japan.
authors.forename: Machiko
authors.initials: M
authors.lastname: Hiramatsu
authors.affiliation: Dept. of Neurology, Univ. of Iowa Carver College of Medicine, Iowa City, Iowa, USA.
authors.forename: Steven W
authors.initials: SW
authors.lastname: Anderson
authors.affiliation: Dept. of Neurology, Univ. of Iowa Carver College of Medicine, Iowa City, Iowa, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Rizzo