Visual Demand of Curves and Fog-Limited Sight Distance and Its Relationship to Brake Response Time

摘要

The report submitted herein is a final report for Task 2 that documents the research progress to date (March 2003-March 2004) in Phase I. In this report, the major results from the literature review are summarized to determine the research needs for the present study, the experimental methods and resultant data are described, diagnostic measures and preliminary algorithms are identified, and human factors recommendations are offered.Two analysts rated the visual, auditory, cognitive, and psychomotor demands of 68 subtasks (e.g., prepare to eat/drink, converse on the cell phone) performed while driving. Ratings were relative to anchors from the U.S. Army IMPRINT modeling tool (0-to-7 scale). Video clips of those subtasks were sampled from the advanced collision avoidance system (ACAS) field operational test (FOT) database, a naturalistic study of driving previously performed by UMTRI. Key findings were: (1) The most demanding tasks were dialing a phone, answering a phone, lighting a cigar or cigarette, dealing with pet and insect distractions, dealing with spilled drinks and food, typing with 2 thumbs, and drinking from a cup, in that order. (2) Demand levels within subtasks were moderately correlated (visual-cognitive=0.68, visual-psychomotor=0.48, cognitive-auditory=0.42, cognitive -psychomotor=0.34) or close to 0. (3) In terms of these ratings, cognitive demands, both per unit time and when weighted by exposure, were consistently double the value of others. (4) Demands varied to a limited degree among road types. (5) There were consistent differences in demand due to driver age and sex. Researchers are encouraged to use the demand ratings provided and extend them to other tasks so tasks can be compared across experiments.