Details:

Creators:
Hanscom, Fred R ; Lerner, Neil D ; Steinberg, Geoffrey V
Hanscom, Fred R ; Lerner, Neil D ; Steinberg, Geoffrey V Less -
Subject/TRT Terms:
[+]
Driver Errors Literature Reviews Perception
Publication/ Report Number:
FHWA-RD-00-022
Resource Type:
Research Paper
TRIS Online Accession Number:
00795349
Corporate Publisher:
United States. Federal Highway Administration
NTL Classification:
NTL-SAFETY AND SECURITY-Accidents;NTL-SAFETY AND SECURITY-Human Factors;NTL-SAFETY AND SECURITY-Highway Safety;
Abstract:
Drivers may make errors that result in a collision with another vehicle, even when they are aware of the presence of the conflicting vehicle. This is because perceptual judgments about time, space, and speed are imperfect, and can lead to misjudgments about the adequacy of a situation to allow some driving maneuver. Drivers may err in thinking there is more time available for the maneuver than is actually the case; or err in thinking the maneuver takes less time to execute than it actually does. Either misperception could lead to a decision to go ahead with a maneuver with less margin of safety than the driver assumes. Misperceptions of the time available or time required for various driving maneuvers under a range of conditions were studied in this project. In the laboratory experiment, research participants viewed video scenes, filmed from a driver's perspective, of a wide variety of situations. For each scene, the viewers made judgments about when some event would occur (e.g., approaching vehicle reaches them) or when some maneuver would be completed (e.g., own vehicle clears roadway when making a crossing maneuver). Participants' judgments were compared with actual values (for time available) or best estimates from engineering equations and empirical data (for time or distance required). A parallel on-the-road experiment, using similar procedures and a subset of the laboratory situations, was used to validate and benchmark the laboratory findings. The study found a general tendency for people to underestimate the time required to complete a maneuver. Across a range of maneuvers, about 60% of all time or distance "required" judgments were underestimated, relative to engineering and empirical estimates. This misjudgment is safety-critical, because driver perception that a maneuver will take less time than is actually the case may lead to decisions to accept maneuver opportunities that actually afford a smaller margin of error than the driver perceives. Such misestimates were particularly common for judgments of the time to achieve the prevailing traffic speed during turning or merging maneuvers, and for the time until one's vehicle reaches an intersection ahead. For judgments of the time "available" for a maneuver, the error was usually in a safety-conservative direction. That is, people felt they had less time than they actually did, so would be less likely to attempt a maneuver. However, even for time available judgments, there were meaningful numbers of safety-critical errors (overestimates of time available), especially for estimates of yellow signal phase time remaining and estimates related to a passing scenario. When the combined errors related to both maneuver requirements and availability were jointly considered, some situations emerged as particularly meriting consideration for safety countermeasures. These included: (1) approach to signalized intersections; (2) turns onto higher-speed roadways; (3) freeway merges; (4) passing; and (5) headway maintenance. Efforts were undertaken to development infrastructure-based countermeasure concepts.
Format:
PDF
Collection(s):
Federal Highway Administration US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:6d097e6bbc5cf51f55ed4160c722437846cda8f35bf39cf293ec1d74190911ed
Download URL:
https://rosap.ntl.bts.gov/view/dot/14008/dot_14008_DS1.pdf
File Type:

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