ABILITY OF DRIVERS TO MAKE CRITICAL PASSING JUDGMENTS
AN INVESTIGATION WAS CONDUCTED TO DETERMINE HOW ACCURATELY DRIVERS ARE ABLE TO ESTIMATE CLEARANCE TIME. ONE OF THE KEY SKILLS REQUIRED BY THE OPERATOR OF A MOTOR VEHICLE IS THE ABILITY TO MAKE SAFE AND ACCURATE JUDGMENTS REQUIRED IN THE OVERTAKING AND PASSING OF ANOTHER VEHICLE. NINETEEN MALE COLLEGE STUDENTS WHOSE AGES RANGED FROM 18 TO 23 YEARS WERE PAID TO PARTICIPATE IN THE STUDY. ALL SUBJECTS HAD SEVERAL YEARS DRIVING EXPERIENCE AND HAD SERVED IN PREVIOUS LABORATORY INVESTIGATIONS IN WHICH THEY HAD BEEN SCREENED FOR VISUAL DEFECTS. A PRELIMINARY TRAINING PROCEDURE WAS FOLLOWED IN WHICH A SUBJECT WAS PICKED UP AT HIS RESIDENCE BY ONE OF THE EXPERIMENTERS IN THE TEST VEHICLE. THE SUBJECT WAS ALLOWED TIME TO BECOME ACQUAINTED WITH THE CHARACTERISTICS OF THE CAR. THE SUBJECT THEN FOLLOWED ABOUT CAR LENGTHS BEHIND THE LEAD CAR AND PRACTICED PASSING THE LEAD CAR. HE WAS THEN INSTRUCTED TO FOLLOW THE LEAD CAR TRAVELLING AT 60 MILES PER HOUR AND NOT PASSING IT. HOWEVER, HE WAS INSTRUCTED TO INDICATE WHEN HE CONSIDERED IT SAFE SAFE TO PASS THE LEAD CAR. THE NUMBER OF OVERESTIMATES AND UNDERESTIMATES MADE BY THE SUBJECTS AND THE MAGNITUDE IN SECONDS OF THE ESTIMATES WERE RECORDED. THERE WAS CONSIDERABLE VARIATION AMONG THE SUBJECTS IN THE ABILITY TO MAKE THE REQUIRED CLEARANCE TIME ESTIMATES. THE STANDARD DEVIATIONS AS COMPUTED FOR THE ESTIMATES OF EACH SUBJECT ARE PRESENTED IN A TABLE. THE NATURE OF THE INVESTIGATION WAS SUCH THAT SUBJECTS WERE REQUIRED TO MAKE WHAT MIGHT BE TERMED CRITICAL JUDGMENTS OF CLEARANCE TIME. ON THE BASIS OF TIMINGS TAKEN BY THE EXPERIMENTER, IT WAS POSSIBLE TO DETERMINE WHETHER THE DRIVER COULD ACTUALLY HAVE PASSED THE CAR SAFELY /OVERESTIMATE/ OR WHETHER HE WOULD NOT HAVE HAD ADEQUATE TIME TO COMPLETE THE PASS /UNDERESTIMATE/. IT WAS FOUND THAT OUT OF A TOTAL OF 190 ESTIMATES, 97 WERE OVERESTIMATES AND 93 WERE UNDERESTIMATES /WHICH WOULD HAVE RESULTED IN AN ACCIDENT/.
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Supplemental Notes:
- Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
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Authors:
- Jones, Howard V
- Heimstra, Norman W
- Publication Date: 1966
Media Info
- Features: References; Tables;
- Pagination: p. 89-92
- Monograph Title: Road user characteristics
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Serial:
- Highway Research Record
- Issue Number: 122
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Accuracy; Car clearances (Railroads); Drivers; Education; Estimates; Methodology; Passing; Test drivers; Time; Vehicles
- Old TRIS Terms: Clearances; Determination; Lead car
- Subject Areas: Highways; Safety and Human Factors; Vehicles and Equipment;
Filing Info
- Accession Number: 00222530
- Record Type: Publication
- Report/Paper Numbers: HS-005 638
- Files: HSL, TRIS, TRB
- Created Date: Nov 18 1994 12:00AM