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https://nap.nationalacademies.org/catalog/27432/critical-issues-in-transportation-for-2024-and-beyond

ACCURACY OF DRIVERS' ESTIMATES OF VEHICLES MILEAGE DRIVEN

ODOMETER READINGS WERE OBTAINED FROM A LARGE SAMPLE OF CARS REGISTERED WITH THE UNIVERSITY OF NORTH CAROLINA IN CHAPEL HILL AND PARKED ON CAMPUS. READINGS WERE OBTAINED AT THE BEGINNING OF THE FALL SEMESTER OF 1969 AND AT THE END OF THE SPRING SEMESTER OF 1970. THUS, IT WAS POSSIBLE TO DETEMINE HOW FAR A PARTICULAR CAR IN THE SAMPLE HAD BEEN DRIVEN DURING A SPECIFIC PERIOD OF TIME. TOWARD THE END OF THE SPRING 1970 SEMESTER, EACH OF THESE CAR OWNERS WAS SENT A QUESTIONNAIRE REQUESTING INFORMATION ABOUT THE CAR THEY USUALLY DROVE AND ABOUT HOW FAR THAT AUTOMOBILE WAS DRIVEN (INCLUDING MILEAGE PUT ON BY OTHER PEOPLE). HENCE, IT WAS POSSIBLE TO COMPARE THE ESTIMATES GIVEN BY THE DRIVERS WITH THE ACTUAL MILEAGE AS DETERMINED BY THE DIFFERENCE IN ODOMETER READINGS. TO DETERMINE WHETHER THERE ARE ANY DRIVER CHARACTERISTICS, SUCH AS AGE, SEX, AMOUNT OF RESPONSIBILITY ASSUMED FOR CAR, AND DEGREE OF INTEREST IN CAR, THAT APPEAR TO BE ASSOCIATED WITH GREATER ACCURACY OF MILEAGE ESTIMTES, THE QUESTIONNAIRE (INCLUDED THIS TYPE OF INFORMATION AND PROVIDED THE BASIS FOR A RESPONSIBILITY INDEX AND AN INTEREST INDEX. AN 80% RETURN OF THE QUESTIONNAIRE WAS OBTAINED. BASED ON THE 505 COMPLETE CASES, THERE IS A SIGNIFICANT CORRELATION COEFFICIENT OF 0.65 BETWEEN THE ESTIMATED AND THE ACTUAL MONTLY MILEAGE. HENCE, IN GENERAL, WHEN THE ACTUAL MILEAGE IS HIGH THE ESTIMATE IS HIGH AND VICE VERSA. ABOUT HALF THE DRIVERS ESTIMTED THEIR MILEAGE WITHIN 200 MILES PER MONTH. HIGH MILEAGE WAS ASSOCIATED WITH LOWER SCORES ON THE RESPONSIBILITY INDEX AND HIGHER SCORES ON THE INTEREST INDEX. HOWEVER, NEITHER INDEX WAS RELATED TO ACCURACY OF MILEAGE ESTIMATES. MALES TENDED TO OVERESTIMATE THEIR MILEAGE, WHILE FEMALES TENDED TO UNDERESTIMATE THEIRS. OVERESTIMATES WERE ALSO ASSOCIATED WITH A LARGE ACCUMULATION OF THE MILEAGE BY SOMEONE OTHER THAN THE RESPONDENT AND WITH LOW CAR MILEAGE. THUS, IT WAS FOUND THAT THE MALE DRIVER WHO HAS LOW CAR MILEAGE AND FOR WHOM MUCH OF THE MILEAGE IS ACCUMULATED BY SOMEONE ELSE TENDS TO OVERESTIMATE THE VEHICLE'S MILEAGE. THE ONLY DRIVER CHARACTERISTICS WHICH APPEAR TO BE ASSOCIATED WITH ACCURACY OF ESTIMATED MILEAGE ARE SEX AND AMOUNT OF MILEAGE PUT ON THE CAR. MALES ARE MORE ACCURATE THAN FEMALES IN THEIR ESTIMATES, AND THE LOW MILEAGE DRIVER IS MORE ACCURATE THAN TH HIGH MILEAGE DRIVER. IN PRACTICE, IN ORDER TO ACHIEVE MORE ACCURATE MILEAGE ESTIMATES THE FOLLOWING EQUATION CAN BE USED: Y=652.29 + 0.55U - 3.52V + 134.33W - 47.51X, WHERE U=ESTIMATED MILEAGE, V=AGE, W=STAFF STATUS, X=INTEREST INDEX. /AUTHOR/

  • Supplemental Notes:
    • APP
  • Corporate Authors:

    University of North Carolina, Chapel Hill

    Highway Safety Research Center
    Chapel Hill, NC  United States  27599
  • Authors:
    • HOUSE, E G
    • Waller, P F
  • Publication Date: 1971-11

Media Info

  • Features: Figures; Tables;
  • Pagination: 23 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00223805
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 17 1972 12:00AM